fix the dates in Statistics & Analysis page does not be processed for daylight saving time

pkg/api/accounts.go

@@ -150,7 +150,7 @@ func (a *AccountsApi) AccountCreateHandler(c *core.WebContext) (any, *errs.Error
 		return nil, errs.NewIncompleteOrIncorrectSubmissionError(err)
 	}
 
-	utcOffset, err := c.GetClientTimezoneOffset()
+	_, utcOffset, err := c.GetClientTimezone()
 
 	if err != nil {
 		log.Warnf(c, "[accounts.AccountCreateHandler] cannot get client timezone offset, because %s", err.Error())
@@ -315,7 +315,7 @@ func (a *AccountsApi) AccountModifyHandler(c *core.WebContext) (any, *errs.Error
 		return nil, errs.ErrAccountIdInvalid
 	}
 
-	utcOffset, err := c.GetClientTimezoneOffset()
+	_, utcOffset, err := c.GetClientTimezone()
 
 	if err != nil {
 		log.Warnf(c, "[accounts.AccountModifyHandler] cannot get client timezone offset, because %s", err.Error())

pkg/api/data_managements.go

@@ -302,13 +302,11 @@ func (a *DataManagementsApi) getExportedFileContent(c *core.WebContext, fileType
 		return nil, "", errs.NewIncompleteOrIncorrectSubmissionError(err)
 	}
 
-	timezone := time.Local
+	timezone, _, err := c.GetClientTimezone()
-	utcOffset, err := c.GetClientTimezoneOffset()
 
 	if err != nil {
 		log.Warnf(c, "[data_managements.getExportedFileContent] cannot get client timezone offset, because %s", err.Error())
-	} else {
+		timezone = time.Local
-		timezone = time.FixedZone("Client Timezone", int(utcOffset)*60)
 	}
 
 	uid := c.GetCurrentUid()

pkg/api/large_language_models.go

@@ -47,14 +47,13 @@ func (a *LargeLanguageModelsApi) RecognizeReceiptImageHandler(c *core.WebContext
 		return nil, errs.ErrLargeLanguageModelProviderNotEnabled
 	}
 
-	utcOffset, err := c.GetClientTimezoneOffset()
+	clientTimezone, utcOffset, err := c.GetClientTimezone()
 
 	if err != nil {
-		log.Warnf(c, "[large_language_models.RecognizeReceiptImageHandler] cannot get client timezone offset, because %s", err.Error())
+		log.Warnf(c, "[large_language_models.RecognizeReceiptImageHandler] cannot get client timezone, because %s", err.Error())
 		return nil, errs.ErrClientTimezoneOffsetInvalid
 	}
 
-	timezone := time.FixedZone("Client Timezone", int(utcOffset)*60)
 	uid := c.GetCurrentUid()
 	user, err := a.users.GetUserById(c, uid)
 
@@ -197,7 +196,7 @@ func (a *LargeLanguageModelsApi) RecognizeReceiptImageHandler(c *core.WebContext
 	}
 
 	systemPromptParams := map[string]any{
-		"CurrentDateTime":          utils.FormatUnixTimeToLongDateTime(time.Now().Unix(), timezone),
+		"CurrentDateTime":          utils.FormatUnixTimeToLongDateTime(time.Now().Unix(), clientTimezone),
 		"AllExpenseCategoryNames":  strings.Join(expenseCategoryNames, "\n"),
 		"AllIncomeCategoryNames":   strings.Join(incomeCategoryNames, "\n"),
 		"AllTransferCategoryNames": strings.Join(transferCategoryNames, "\n"),

pkg/api/transactions.go

@@ -7,6 +7,7 @@ import (
 	"math"
 	"sort"
 	"strings"
+	"time"
 
 	orderedmap "github.com/wk8/go-ordered-map/v2"
 
@@ -120,10 +121,10 @@ func (a *TransactionsApi) TransactionListHandler(c *core.WebContext) (any, *errs
 		return nil, errs.NewIncompleteOrIncorrectSubmissionError(err)
 	}
 
-	utcOffset, err := c.GetClientTimezoneOffset()
+	clientTimezone, _, err := c.GetClientTimezone()
 
 	if err != nil {
-		log.Warnf(c, "[transactions.TransactionListHandler] cannot get client timezone offset, because %s", err.Error())
+		log.Warnf(c, "[transactions.TransactionListHandler] cannot get client timezone, because %s", err.Error())
 		return nil, errs.ErrClientTimezoneOffsetInvalid
 	}
 
@@ -191,7 +192,7 @@ func (a *TransactionsApi) TransactionListHandler(c *core.WebContext) (any, *errs
 		transactions = transactions[:transactionListReq.Count]
 	}
 
-	transactionResult, err := a.getTransactionResponseListResult(c, user, transactions, utcOffset, transactionListReq.WithPictures, transactionListReq.TrimAccount, transactionListReq.TrimCategory, transactionListReq.TrimTag)
+	transactionResult, err := a.getTransactionResponseListResult(c, user, transactions, clientTimezone, transactionListReq.WithPictures, transactionListReq.TrimAccount, transactionListReq.TrimCategory, transactionListReq.TrimTag)
 
 	if err != nil {
 		log.Errorf(c, "[transactions.TransactionListHandler] failed to assemble transaction result for user \"uid:%d\", because %s", uid, err.Error())
@@ -223,10 +224,10 @@ func (a *TransactionsApi) TransactionMonthListHandler(c *core.WebContext) (any,
 		return nil, errs.NewIncompleteOrIncorrectSubmissionError(err)
 	}
 
-	utcOffset, err := c.GetClientTimezoneOffset()
+	clientTimezone, _, err := c.GetClientTimezone()
 
 	if err != nil {
-		log.Warnf(c, "[transactions.TransactionMonthListHandler] cannot get client timezone offset, because %s", err.Error())
+		log.Warnf(c, "[transactions.TransactionMonthListHandler] cannot get client timezone, because %s", err.Error())
 		return nil, errs.ErrClientTimezoneOffsetInvalid
 	}
 
@@ -274,7 +275,7 @@ func (a *TransactionsApi) TransactionMonthListHandler(c *core.WebContext) (any,
 		return nil, errs.Or(err, errs.ErrOperationFailed)
 	}
 
-	transactionResult, err := a.getTransactionResponseListResult(c, user, transactions, utcOffset, transactionListReq.WithPictures, transactionListReq.TrimAccount, transactionListReq.TrimCategory, transactionListReq.TrimTag)
+	transactionResult, err := a.getTransactionResponseListResult(c, user, transactions, clientTimezone, transactionListReq.WithPictures, transactionListReq.TrimAccount, transactionListReq.TrimCategory, transactionListReq.TrimTag)
 
 	if err != nil {
 		log.Errorf(c, "[transactions.TransactionMonthListHandler] failed to assemble transaction result for user \"uid:%d\", because %s", uid, err.Error())
@@ -299,10 +300,10 @@ func (a *TransactionsApi) TransactionListAllHandler(c *core.WebContext) (any, *e
 		return nil, errs.NewIncompleteOrIncorrectSubmissionError(err)
 	}
 
-	utcOffset, err := c.GetClientTimezoneOffset()
+	clientTimezone, _, err := c.GetClientTimezone()
 
 	if err != nil {
-		log.Warnf(c, "[transactions.TransactionListAllHandler] cannot get client timezone offset, because %s", err.Error())
+		log.Warnf(c, "[transactions.TransactionListAllHandler] cannot get client timezone, because %s", err.Error())
 		return nil, errs.ErrClientTimezoneOffsetInvalid
 	}
 
@@ -361,7 +362,7 @@ func (a *TransactionsApi) TransactionListAllHandler(c *core.WebContext) (any, *e
 		return nil, errs.Or(err, errs.ErrOperationFailed)
 	}
 
-	transactionResult, err := a.getTransactionResponseListResult(c, user, allTransactions, utcOffset, transactionAllListReq.WithPictures, transactionAllListReq.TrimAccount, transactionAllListReq.TrimCategory, transactionAllListReq.TrimTag)
+	transactionResult, err := a.getTransactionResponseListResult(c, user, allTransactions, clientTimezone, transactionAllListReq.WithPictures, transactionAllListReq.TrimAccount, transactionAllListReq.TrimCategory, transactionAllListReq.TrimTag)
 
 	if err != nil {
 		log.Errorf(c, "[transactions.TransactionListAllHandler] failed to assemble transaction result for user \"uid:%d\", because %s", uid, err.Error())
@@ -381,10 +382,10 @@ func (a *TransactionsApi) TransactionReconciliationStatementHandler(c *core.WebC
 		return nil, errs.NewIncompleteOrIncorrectSubmissionError(err)
 	}
 
-	utcOffset, err := c.GetClientTimezoneOffset()
+	clientTimezone, _, err := c.GetClientTimezone()
 
 	if err != nil {
-		log.Warnf(c, "[transactions.TransactionReconciliationStatementHandler] cannot get client timezone offset, because %s", err.Error())
+		log.Warnf(c, "[transactions.TransactionReconciliationStatementHandler] cannot get client timezone, because %s", err.Error())
 		return nil, errs.ErrClientTimezoneOffsetInvalid
 	}
 
@@ -440,7 +441,7 @@ func (a *TransactionsApi) TransactionReconciliationStatementHandler(c *core.WebC
 		transactionAccountBalanceMap[transactionWithBalance.RelatedId] = transactionWithBalance
 	}
 
-	transactionResult, err := a.getTransactionResponseListResult(c, user, transactions, utcOffset, false, true, true, true)
+	transactionResult, err := a.getTransactionResponseListResult(c, user, transactions, clientTimezone, false, true, true, true)
 
 	if err != nil {
 		log.Errorf(c, "[transactions.TransactionReconciliationStatementHandler] failed to assemble transaction result for user \"uid:%d\", because %s", uid, err.Error())
@@ -489,10 +490,10 @@ func (a *TransactionsApi) TransactionStatisticsHandler(c *core.WebContext) (any,
 		return nil, errs.NewIncompleteOrIncorrectSubmissionError(err)
 	}
 
-	utcOffset, err := c.GetClientTimezoneOffset()
+	clientTimezone, utfOffset, err := c.GetClientTimezone()
 
 	if err != nil {
-		log.Warnf(c, "[transactions.TransactionStatisticsHandler] cannot get client timezone offset, because %s", err.Error())
+		log.Warnf(c, "[transactions.TransactionStatisticsHandler] cannot get client timezone, because %s", err.Error())
 		return nil, errs.ErrClientTimezoneOffsetInvalid
 	}
 
@@ -509,7 +510,7 @@ func (a *TransactionsApi) TransactionStatisticsHandler(c *core.WebContext) (any,
 	}
 
 	uid := c.GetCurrentUid()
-	totalAmounts, err := a.transactions.GetAccountsAndCategoriesTotalInflowAndOutflow(c, uid, statisticReq.StartTime, statisticReq.EndTime, tagFilters, noTags, statisticReq.Keyword, utcOffset, statisticReq.UseTransactionTimezone)
+	totalAmounts, err := a.transactions.GetAccountsAndCategoriesTotalInflowAndOutflow(c, uid, statisticReq.StartTime, statisticReq.EndTime, tagFilters, noTags, statisticReq.Keyword, utfOffset, clientTimezone, statisticReq.UseTransactionTimezone)
 
 	if err != nil {
 		log.Errorf(c, "[transactions.TransactionStatisticsHandler] failed to get accounts and categories total income and expense for user \"uid:%d\", because %s", uid, err.Error())
@@ -550,10 +551,10 @@ func (a *TransactionsApi) TransactionStatisticsTrendsHandler(c *core.WebContext)
 		return nil, errs.NewIncompleteOrIncorrectSubmissionError(err)
 	}
 
-	utcOffset, err := c.GetClientTimezoneOffset()
+	clientTimezone, _, err := c.GetClientTimezone()
 
 	if err != nil {
-		log.Warnf(c, "[transactions.TransactionStatisticsTrendsHandler] cannot get client timezone offset, because %s", err.Error())
+		log.Warnf(c, "[transactions.TransactionStatisticsTrendsHandler] cannot get client timezone, because %s", err.Error())
 		return nil, errs.ErrClientTimezoneOffsetInvalid
 	}
 
@@ -577,7 +578,7 @@ func (a *TransactionsApi) TransactionStatisticsTrendsHandler(c *core.WebContext)
 	}
 
 	uid := c.GetCurrentUid()
-	allMonthlyTotalAmounts, err := a.transactions.GetAccountsAndCategoriesMonthlyInflowAndOutflow(c, uid, startYear, startMonth, endYear, endMonth, tagFilters, noTags, statisticTrendsReq.Keyword, utcOffset, statisticTrendsReq.UseTransactionTimezone)
+	allMonthlyTotalAmounts, err := a.transactions.GetAccountsAndCategoriesMonthlyInflowAndOutflow(c, uid, startYear, startMonth, endYear, endMonth, tagFilters, noTags, statisticTrendsReq.Keyword, clientTimezone, statisticTrendsReq.UseTransactionTimezone)
 
 	if err != nil {
 		log.Errorf(c, "[transactions.TransactionStatisticsTrendsHandler] failed to get accounts and categories total income and expense for user \"uid:%d\", because %s", uid, err.Error())
@@ -625,10 +626,10 @@ func (a *TransactionsApi) TransactionStatisticsAssetTrendsHandler(c *core.WebCon
 		return nil, errs.NewIncompleteOrIncorrectSubmissionError(err)
 	}
 
-	utcOffset, err := c.GetClientTimezoneOffset()
+	clientTimezone, _, err := c.GetClientTimezone()
 
 	if err != nil {
-		log.Warnf(c, "[transactions.TransactionStatisticsAssetTrendsHandler] cannot get client timezone offset, because %s", err.Error())
+		log.Warnf(c, "[transactions.TransactionStatisticsAssetTrendsHandler] cannot get client timezone, because %s", err.Error())
 		return nil, errs.ErrClientTimezoneOffsetInvalid
 	}
 
@@ -646,7 +647,7 @@ func (a *TransactionsApi) TransactionStatisticsAssetTrendsHandler(c *core.WebCon
 		minTransactionTime = utils.GetMinTransactionTimeFromUnixTime(statisticAssetTrendsReq.StartTime)
 	}
 
-	accountDailyBalances, err := a.transactions.GetAllAccountsDailyOpeningAndClosingBalance(c, uid, maxTransactionTime, minTransactionTime, utcOffset)
+	accountDailyBalances, err := a.transactions.GetAllAccountsDailyOpeningAndClosingBalance(c, uid, maxTransactionTime, minTransactionTime, clientTimezone)
 
 	if err != nil {
 		log.Errorf(c, "[transactions.TransactionStatisticsAssetTrendsHandler] failed to get transactions from \"%d\" to \"%d\" for user \"uid:%d\", because %s", statisticAssetTrendsReq.StartTime, statisticAssetTrendsReq.EndTime, uid, err.Error())
@@ -726,10 +727,10 @@ func (a *TransactionsApi) TransactionAmountsHandler(c *core.WebContext) (any, *e
 		}
 	}
 
-	utcOffset, err := c.GetClientTimezoneOffset()
+	clientTimezone, utfOffset, err := c.GetClientTimezone()
 
 	if err != nil {
-		log.Warnf(c, "[transactions.TransactionAmountsHandler] cannot get client timezone offset, because %s", err.Error())
+		log.Warnf(c, "[transactions.TransactionAmountsHandler] cannot get client timezone, because %s", err.Error())
 		return nil, errs.ErrClientTimezoneOffsetInvalid
 	}
 
@@ -748,7 +749,7 @@ func (a *TransactionsApi) TransactionAmountsHandler(c *core.WebContext) (any, *e
 	for i := 0; i < len(requestItems); i++ {
 		requestItem := requestItems[i]
 
-		incomeAmounts, expenseAmounts, err := a.transactions.GetAccountsTotalIncomeAndExpense(c, uid, requestItem.StartTime, requestItem.EndTime, excludeAccountIds, excludeCategoryIds, utcOffset, transactionAmountsReq.UseTransactionTimezone)
+		incomeAmounts, expenseAmounts, err := a.transactions.GetAccountsTotalIncomeAndExpense(c, uid, requestItem.StartTime, requestItem.EndTime, excludeAccountIds, excludeCategoryIds, utfOffset, clientTimezone, transactionAmountsReq.UseTransactionTimezone)
 
 		if err != nil {
 			log.Errorf(c, "[transactions.TransactionAmountsHandler] failed to get transaction amounts item for user \"uid:%d\", because %s", uid, err.Error())
@@ -829,10 +830,10 @@ func (a *TransactionsApi) TransactionGetHandler(c *core.WebContext) (any, *errs.
 		return nil, errs.NewIncompleteOrIncorrectSubmissionError(err)
 	}
 
-	utcOffset, err := c.GetClientTimezoneOffset()
+	clientTimezone, _, err := c.GetClientTimezone()
 
 	if err != nil {
-		log.Warnf(c, "[transactions.TransactionGetHandler] cannot get client timezone offset, because %s", err.Error())
+		log.Warnf(c, "[transactions.TransactionGetHandler] cannot get client timezone, because %s", err.Error())
 		return nil, errs.ErrClientTimezoneOffsetInvalid
 	}
 
@@ -918,7 +919,7 @@ func (a *TransactionsApi) TransactionGetHandler(c *core.WebContext) (any, *errs.
 		}
 	}
 
-	transactionEditable := transaction.IsEditable(user, utcOffset, accountMap[transaction.AccountId], accountMap[transaction.RelatedAccountId])
+	transactionEditable := transaction.IsEditable(user, clientTimezone, accountMap[transaction.AccountId], accountMap[transaction.RelatedAccountId])
 	transactionTagIds := allTransactionTagIds[transaction.TransactionId]
 	transactionResp := transaction.ToTransactionInfoResponse(transactionTagIds, transactionEditable)
 
@@ -959,6 +960,13 @@ func (a *TransactionsApi) TransactionCreateHandler(c *core.WebContext) (any, *er
 		return nil, errs.NewIncompleteOrIncorrectSubmissionError(err)
 	}
 
+	clientTimezone, _, err := c.GetClientTimezone()
+
+	if err != nil {
+		log.Warnf(c, "[transactions.TransactionCreateHandler] cannot get client timezone, because %s", err.Error())
+		return nil, errs.ErrClientTimezoneOffsetInvalid
+	}
+
 	tagIds, err := utils.StringArrayToInt64Array(transactionCreateReq.TagIds)
 
 	if err != nil {
@@ -1016,7 +1024,7 @@ func (a *TransactionsApi) TransactionCreateHandler(c *core.WebContext) (any, *er
 	}
 
 	transaction := a.createNewTransactionModel(uid, &transactionCreateReq, c.ClientIP())
-	transactionEditable := user.CanEditTransactionByTransactionTime(transaction.TransactionTime, transactionCreateReq.UtcOffset)
+	transactionEditable := user.CanEditTransactionByTransactionTime(transaction.TransactionTime, clientTimezone)
 
 	if !transactionEditable {
 		return nil, errs.ErrCannotCreateTransactionWithThisTransactionTime
@@ -1089,6 +1097,13 @@ func (a *TransactionsApi) TransactionModifyHandler(c *core.WebContext) (any, *er
 		return nil, errs.NewIncompleteOrIncorrectSubmissionError(err)
 	}
 
+	clientTimezone, _, err := c.GetClientTimezone()
+
+	if err != nil {
+		log.Warnf(c, "[transactions.TransactionModifyHandler] cannot get client timezone, because %s", err.Error())
+		return nil, errs.ErrClientTimezoneOffsetInvalid
+	}
+
 	tagIds, err := utils.StringArrayToInt64Array(transactionModifyReq.TagIds)
 
 	if err != nil {
@@ -1202,8 +1217,8 @@ func (a *TransactionsApi) TransactionModifyHandler(c *core.WebContext) (any, *er
 		return nil, errs.ErrNothingWillBeUpdated
 	}
 
-	transactionEditable := user.CanEditTransactionByTransactionTime(transaction.TransactionTime, transaction.TimezoneUtcOffset)
+	transactionEditable := user.CanEditTransactionByTransactionTime(transaction.TransactionTime, clientTimezone)
-	newTransactionEditable := user.CanEditTransactionByTransactionTime(newTransaction.TransactionTime, transactionModifyReq.UtcOffset)
+	newTransactionEditable := user.CanEditTransactionByTransactionTime(newTransaction.TransactionTime, clientTimezone)
 
 	if !transactionEditable || !newTransactionEditable {
 		return nil, errs.ErrCannotModifyTransactionWithThisTransactionTime
@@ -1339,10 +1354,10 @@ func (a *TransactionsApi) TransactionDeleteHandler(c *core.WebContext) (any, *er
 		return nil, errs.NewIncompleteOrIncorrectSubmissionError(err)
 	}
 
-	utcOffset, err := c.GetClientTimezoneOffset()
+	clientTimezone, _, err := c.GetClientTimezone()
 
 	if err != nil {
-		log.Warnf(c, "[transactions.TransactionDeleteHandler] cannot get client timezone offset, because %s", err.Error())
+		log.Warnf(c, "[transactions.TransactionDeleteHandler] cannot get client timezone, because %s", err.Error())
 		return nil, errs.ErrClientTimezoneOffsetInvalid
 	}
 
@@ -1369,7 +1384,7 @@ func (a *TransactionsApi) TransactionDeleteHandler(c *core.WebContext) (any, *er
 		return nil, errs.ErrTransactionTypeInvalid
 	}
 
-	transactionEditable := user.CanEditTransactionByTransactionTime(transaction.TransactionTime, utcOffset)
+	transactionEditable := user.CanEditTransactionByTransactionTime(transaction.TransactionTime, clientTimezone)
 
 	if !transactionEditable {
 		return nil, errs.ErrCannotDeleteTransactionWithThisTransactionTime
@@ -1473,7 +1488,7 @@ func (a *TransactionsApi) TransactionParseImportFileHandler(c *core.WebContext)
 		return nil, errs.ErrParameterInvalid
 	}
 
-	utcOffset, err := c.GetClientTimezoneOffset()
+	_, utcOffset, err := c.GetClientTimezone()
 
 	if err != nil {
 		log.Warnf(c, "[transactions.TransactionParseImportFileHandler] cannot get client timezone offset, because %s", err.Error())
@@ -1704,6 +1719,13 @@ func (a *TransactionsApi) TransactionImportHandler(c *core.WebContext) (any, *er
 		return nil, errs.NewIncompleteOrIncorrectSubmissionError(err)
 	}
 
+	clientTimezone, _, err := c.GetClientTimezone()
+
+	if err != nil {
+		log.Warnf(c, "[transactions.TransactionImportHandler] cannot get client timezone, because %s", err.Error())
+		return nil, errs.ErrClientTimezoneOffsetInvalid
+	}
+
 	uid := c.GetCurrentUid()
 
 	if a.CurrentConfig().EnableDuplicateSubmissionsCheck && transactionImportReq.ClientSessionId != "" {
@@ -1789,7 +1811,7 @@ func (a *TransactionsApi) TransactionImportHandler(c *core.WebContext) (any, *er
 	for i := 0; i < len(transactionImportReq.Transactions); i++ {
 		transactionCreateReq := transactionImportReq.Transactions[i]
 		transaction := a.createNewTransactionModel(uid, transactionCreateReq, c.ClientIP())
-		transactionEditable := user.CanEditTransactionByTransactionTime(transaction.TransactionTime, transactionCreateReq.UtcOffset)
+		transactionEditable := user.CanEditTransactionByTransactionTime(transaction.TransactionTime, clientTimezone)
 
 		if !transactionEditable {
 			return nil, errs.ErrCannotCreateTransactionWithThisTransactionTime
@@ -1906,7 +1928,7 @@ func (a *TransactionsApi) getTransactionTagInfoResponses(tagIds []int64, allTran
 	return allTags
 }
 
-func (a *TransactionsApi) getTransactionResponseListResult(c *core.WebContext, user *models.User, transactions []*models.Transaction, utcOffset int16, withPictures bool, trimAccount bool, trimCategory bool, trimTag bool) (models.TransactionInfoResponseSlice, error) {
+func (a *TransactionsApi) getTransactionResponseListResult(c *core.WebContext, user *models.User, transactions []*models.Transaction, clientTimezone *time.Location, withPictures bool, trimAccount bool, trimCategory bool, trimTag bool) (models.TransactionInfoResponseSlice, error) {
 	uid := user.Uid
 	transactionIds := make([]int64, len(transactions))
 	accountIds := make([]int64, 0, len(transactions)*2)
@@ -1985,7 +2007,7 @@ func (a *TransactionsApi) getTransactionResponseListResult(c *core.WebContext, u
 			transaction = a.transactions.GetRelatedTransferTransaction(transaction)
 		}
 
-		transactionEditable := transaction.IsEditable(user, utcOffset, allAccounts[transaction.AccountId], allAccounts[transaction.RelatedAccountId])
+		transactionEditable := transaction.IsEditable(user, clientTimezone, allAccounts[transaction.AccountId], allAccounts[transaction.RelatedAccountId])
 		transactionTagIds := allTransactionTagIds[transaction.TransactionId]
 		result[i] = transaction.ToTransactionInfoResponse(transactionTagIds, transactionEditable)
 

pkg/core/context_web.go

@@ -4,6 +4,7 @@ import (
 	"net"
 	"strconv"
 	"strings"
+	"time"
 
 	"github.com/gin-gonic/gin"
 
@@ -25,6 +26,9 @@ const RemoteClientPortHeader = "X-Real-Port"
 // ClientTimezoneOffsetHeaderName represents the header name of client timezone offset
 const ClientTimezoneOffsetHeaderName = "X-Timezone-Offset"
 
+// ClientTimezoneNameHeaderName represents the header name of client timezone name
+const ClientTimezoneNameHeaderName = "X-Timezone-Name"
+
 const tokenHeaderName = "Authorization"
 const tokenHeaderValuePrefix = "bearer "
 const tokenQueryStringParam = "token"
@@ -183,16 +187,24 @@ func (c *WebContext) GetClientLocale() string {
 	return value
 }
 
-// GetClientTimezoneOffset returns the client timezone offset
+func (c *WebContext) GetClientTimezone() (*time.Location, int16, error) {
-func (c *WebContext) GetClientTimezoneOffset() (int16, error) {
+	utcOffset, err := c.getClientTimezoneOffset()
-	value := c.GetHeader(ClientTimezoneOffsetHeaderName)
-	offset, err := strconv.Atoi(value)
 
 	if err != nil {
-		return 0, err
+		return nil, 0, err
 	}
 
-	return int16(offset), nil
+	timezoneName := c.getClientTimezoneName()
+
+	if timezoneName != "" {
+		location, err := time.LoadLocation(timezoneName)
+
+		if err == nil && location != nil {
+			return location, utcOffset, nil
+		}
+	}
+
+	return time.FixedZone("Client Fixed Timezone", int(utcOffset)*60), utcOffset, nil
 }
 
 // SetResponseError sets the response error
@@ -211,6 +223,25 @@ func (c *WebContext) GetResponseError() *errs.Error {
 	return err.(*errs.Error)
 }
 
+// GetClientTimezoneOffset returns the client timezone offset
+func (c *WebContext) getClientTimezoneOffset() (int16, error) {
+	value := c.GetHeader(ClientTimezoneOffsetHeaderName)
+	offset, err := strconv.Atoi(value)
+
+	if err != nil {
+		return 0, err
+	}
+
+	return int16(offset), nil
+}
+
+// GetClientTimezoneName returns the client timezone name
+func (c *WebContext) getClientTimezoneName() string {
+	value := c.GetHeader(ClientTimezoneNameHeaderName)
+
+	return value
+}
+
 // WrapWebContext returns a context wrapped by this file
 func WrapWebContext(ginCtx *gin.Context) *WebContext {
 	return &WebContext{

pkg/mcp/add_transaction_tool_handler.go

@@ -3,6 +3,7 @@ package mcp
 import (
 	"encoding/json"
 	"reflect"
+	"time"
 
 	"github.com/mayswind/ezbookkeeping/pkg/core"
 	"github.com/mayswind/ezbookkeeping/pkg/errs"
@@ -177,7 +178,7 @@ func (h *mcpAddTransactionToolHandler) Handle(c *core.WebContext, callToolReq *M
 		return nil, nil, err
 	}
 
-	transactionEditable := user.CanEditTransactionByTransactionTime(transaction.TransactionTime, transaction.TimezoneUtcOffset)
+	transactionEditable := user.CanEditTransactionByTransactionTime(transaction.TransactionTime, time.FixedZone("Transaction Timezone", int(transaction.TimezoneUtcOffset)*60))
 
 	if !transactionEditable {
 		return nil, nil, errs.ErrCannotCreateTransactionWithThisTransactionTime

pkg/models/transaction.go

@@ -3,6 +3,7 @@ package models
 import (
 	"fmt"
 	"strings"
+	"time"
 
 	"github.com/mayswind/ezbookkeeping/pkg/errs"
 	"github.com/mayswind/ezbookkeeping/pkg/utils"
@@ -511,8 +512,8 @@ func ParseTransactionTagFilter(tagFilterStr string) ([]*TransactionTagFilter, er
 }
 
 // IsEditable returns whether this transaction can be edited
-func (t *Transaction) IsEditable(currentUser *User, utcOffset int16, account *Account, relatedAccount *Account) bool {
+func (t *Transaction) IsEditable(currentUser *User, clientTimezone *time.Location, account *Account, relatedAccount *Account) bool {
-	if currentUser == nil || !currentUser.CanEditTransactionByTransactionTime(t.TransactionTime, utcOffset) {
+	if currentUser == nil || !currentUser.CanEditTransactionByTransactionTime(t.TransactionTime, clientTimezone) {
 		return false
 	}
 

pkg/models/user.go

@@ -230,7 +230,7 @@ type UserProfileResponse struct {
 }
 
 // CanEditTransactionByTransactionTime returns whether this user can edit transaction with specified transaction time
-func (u *User) CanEditTransactionByTransactionTime(transactionTime int64, utcOffset int16) bool {
+func (u *User) CanEditTransactionByTransactionTime(transactionTime int64, clientTimezone *time.Location) bool {
 	if u.TransactionEditScope == TRANSACTION_EDIT_SCOPE_NONE {
 		return false
 	} else if u.TransactionEditScope == TRANSACTION_EDIT_SCOPE_ALL {
@@ -245,8 +245,7 @@ func (u *User) CanEditTransactionByTransactionTime(transactionTime int64, utcOff
 		return transactionUnixTime >= now.Unix()-24*60*60
 	}
 
-	clientLocation := time.FixedZone("Client Timezone", int(utcOffset)*60)
+	clientNow := now.In(clientTimezone)
-	clientNow := now.In(clientLocation)
 	clientTodayFirstUnixTime := clientNow.Unix() - int64(clientNow.Hour()*60*60+clientNow.Minute()*60+clientNow.Second())
 
 	if u.TransactionEditScope == TRANSACTION_EDIT_SCOPE_TODAY_OR_LATER {

pkg/models/user_test.go

@@ -15,7 +15,8 @@ func TestUserCanEditTransactionByTransactionTime_ScopeIsNone(t *testing.T) {
 		TransactionEditScope: TRANSACTION_EDIT_SCOPE_NONE,
 	}
 
-	assert.Equal(t, false, user.CanEditTransactionByTransactionTime(utils.GetMinTransactionTimeFromUnixTime(time.Now().Unix()), utils.GetServerTimezoneOffsetMinutes()))
+	timezone := time.FixedZone("Timezone", int(utils.GetServerTimezoneOffsetMinutes())*60)
+	assert.Equal(t, false, user.CanEditTransactionByTransactionTime(utils.GetMinTransactionTimeFromUnixTime(time.Now().Unix()), timezone))
 }
 
 func TestUserCanEditTransactionByTransactionTime_ScopeIsAll(t *testing.T) {
@@ -23,7 +24,8 @@ func TestUserCanEditTransactionByTransactionTime_ScopeIsAll(t *testing.T) {
 		TransactionEditScope: TRANSACTION_EDIT_SCOPE_ALL,
 	}
 
-	assert.Equal(t, true, user.CanEditTransactionByTransactionTime(utils.GetMinTransactionTimeFromUnixTime(time.Now().Unix()), utils.GetServerTimezoneOffsetMinutes()))
+	timezone := time.FixedZone("Timezone", int(utils.GetServerTimezoneOffsetMinutes())*60)
+	assert.Equal(t, true, user.CanEditTransactionByTransactionTime(utils.GetMinTransactionTimeFromUnixTime(time.Now().Unix()), timezone))
 }
 
 func TestUserCanEditTransactionByTransactionTime_ScopeIsTodayOrLater(t *testing.T) {
@@ -32,13 +34,14 @@ func TestUserCanEditTransactionByTransactionTime_ScopeIsTodayOrLater(t *testing.
 	}
 
 	now := time.Now()
+	timezone := time.FixedZone("Timezone", int(utils.GetServerTimezoneOffsetMinutes())*60)
 	todayFirstDatetime := time.Date(now.Year(), now.Month(), now.Day(), 0, 0, 0, 0, time.Local)
 	yesterdayLastDatetime := todayFirstDatetime.Add(-1 * time.Second)
 	todayLastDatetime := yesterdayLastDatetime.Add(24 * time.Hour)
 
-	assert.Equal(t, true, user.CanEditTransactionByTransactionTime(utils.GetMinTransactionTimeFromUnixTime(todayFirstDatetime.Unix()), utils.GetServerTimezoneOffsetMinutes()))
+	assert.Equal(t, true, user.CanEditTransactionByTransactionTime(utils.GetMinTransactionTimeFromUnixTime(todayFirstDatetime.Unix()), timezone))
-	assert.Equal(t, true, user.CanEditTransactionByTransactionTime(utils.GetMinTransactionTimeFromUnixTime(todayLastDatetime.Unix()), utils.GetServerTimezoneOffsetMinutes()))
+	assert.Equal(t, true, user.CanEditTransactionByTransactionTime(utils.GetMinTransactionTimeFromUnixTime(todayLastDatetime.Unix()), timezone))
-	assert.Equal(t, false, user.CanEditTransactionByTransactionTime(utils.GetMinTransactionTimeFromUnixTime(yesterdayLastDatetime.Unix()), utils.GetServerTimezoneOffsetMinutes()))
+	assert.Equal(t, false, user.CanEditTransactionByTransactionTime(utils.GetMinTransactionTimeFromUnixTime(yesterdayLastDatetime.Unix()), timezone))
 }
 
 func TestUserCanEditTransactionByTransactionTime_ScopeIsLast24HourOrLater(t *testing.T) {
@@ -47,10 +50,11 @@ func TestUserCanEditTransactionByTransactionTime_ScopeIsLast24HourOrLater(t *tes
 	}
 
 	now := time.Now()
+	timezone := time.FixedZone("Timezone", int(utils.GetServerTimezoneOffsetMinutes())*60)
 	twentyfourHourBeforeDatetime := now.Add(-24 * time.Hour).Add(-1 * time.Second)
 
-	assert.Equal(t, false, user.CanEditTransactionByTransactionTime(utils.GetMinTransactionTimeFromUnixTime(twentyfourHourBeforeDatetime.Unix()), utils.GetServerTimezoneOffsetMinutes()))
+	assert.Equal(t, false, user.CanEditTransactionByTransactionTime(utils.GetMinTransactionTimeFromUnixTime(twentyfourHourBeforeDatetime.Unix()), timezone))
-	assert.Equal(t, true, user.CanEditTransactionByTransactionTime(utils.GetMinTransactionTimeFromUnixTime(twentyfourHourBeforeDatetime.Add(1*time.Second).Unix()), utils.GetServerTimezoneOffsetMinutes()))
+	assert.Equal(t, true, user.CanEditTransactionByTransactionTime(utils.GetMinTransactionTimeFromUnixTime(twentyfourHourBeforeDatetime.Add(1*time.Second).Unix()), timezone))
 }
 
 func TestUserCanEditTransactionByTransactionTime_ScopeIsThisWeekOrLater(t *testing.T) {
@@ -60,6 +64,7 @@ func TestUserCanEditTransactionByTransactionTime_ScopeIsThisWeekOrLater(t *testi
 	}
 
 	now := time.Now()
+	timezone := time.FixedZone("Timezone", int(utils.GetServerTimezoneOffsetMinutes())*60)
 	thisWeekFirstDatetime := time.Date(now.Year(), now.Month(), now.Day(), 0, 0, 0, 0, time.Local)
 
 	if thisWeekFirstDatetime.Weekday() == time.Sunday {
@@ -71,9 +76,9 @@ func TestUserCanEditTransactionByTransactionTime_ScopeIsThisWeekOrLater(t *testi
 	lastWeekLastDatetime := thisWeekFirstDatetime.Add(-1 * time.Second)
 	thisWeekLastDatetime := lastWeekLastDatetime.Add(24 * time.Hour)
 
-	assert.Equal(t, true, user.CanEditTransactionByTransactionTime(utils.GetMinTransactionTimeFromUnixTime(thisWeekFirstDatetime.Unix()), utils.GetServerTimezoneOffsetMinutes()))
+	assert.Equal(t, true, user.CanEditTransactionByTransactionTime(utils.GetMinTransactionTimeFromUnixTime(thisWeekFirstDatetime.Unix()), timezone))
-	assert.Equal(t, true, user.CanEditTransactionByTransactionTime(utils.GetMinTransactionTimeFromUnixTime(thisWeekLastDatetime.Unix()), utils.GetServerTimezoneOffsetMinutes()))
+	assert.Equal(t, true, user.CanEditTransactionByTransactionTime(utils.GetMinTransactionTimeFromUnixTime(thisWeekLastDatetime.Unix()), timezone))
-	assert.Equal(t, false, user.CanEditTransactionByTransactionTime(utils.GetMinTransactionTimeFromUnixTime(lastWeekLastDatetime.Unix()), utils.GetServerTimezoneOffsetMinutes()))
+	assert.Equal(t, false, user.CanEditTransactionByTransactionTime(utils.GetMinTransactionTimeFromUnixTime(lastWeekLastDatetime.Unix()), timezone))
 }
 
 func TestUserCanEditTransactionByTransactionTime_ScopeIsThisMonthOrLater(t *testing.T) {
@@ -82,13 +87,14 @@ func TestUserCanEditTransactionByTransactionTime_ScopeIsThisMonthOrLater(t *test
 	}
 
 	now := time.Now()
+	timezone := time.FixedZone("Timezone", int(utils.GetServerTimezoneOffsetMinutes())*60)
 	thisMonthFirstDatetime := time.Date(now.Year(), now.Month(), 1, 0, 0, 0, 0, time.Local)
 	lastMonthLastDatetime := thisMonthFirstDatetime.Add(-1 * time.Second)
 	thisMonthLastDatetime := lastMonthLastDatetime.Add(24 * time.Hour)
 
-	assert.Equal(t, true, user.CanEditTransactionByTransactionTime(utils.GetMinTransactionTimeFromUnixTime(thisMonthFirstDatetime.Unix()), utils.GetServerTimezoneOffsetMinutes()))
+	assert.Equal(t, true, user.CanEditTransactionByTransactionTime(utils.GetMinTransactionTimeFromUnixTime(thisMonthFirstDatetime.Unix()), timezone))
-	assert.Equal(t, true, user.CanEditTransactionByTransactionTime(utils.GetMinTransactionTimeFromUnixTime(thisMonthLastDatetime.Unix()), utils.GetServerTimezoneOffsetMinutes()))
+	assert.Equal(t, true, user.CanEditTransactionByTransactionTime(utils.GetMinTransactionTimeFromUnixTime(thisMonthLastDatetime.Unix()), timezone))
-	assert.Equal(t, false, user.CanEditTransactionByTransactionTime(utils.GetMinTransactionTimeFromUnixTime(lastMonthLastDatetime.Unix()), utils.GetServerTimezoneOffsetMinutes()))
+	assert.Equal(t, false, user.CanEditTransactionByTransactionTime(utils.GetMinTransactionTimeFromUnixTime(lastMonthLastDatetime.Unix()), timezone))
 }
 
 func TestUserCanEditTransactionByTransactionTime_ScopeIsThisYearOrLater(t *testing.T) {
@@ -97,11 +103,12 @@ func TestUserCanEditTransactionByTransactionTime_ScopeIsThisYearOrLater(t *testi
 	}
 
 	now := time.Now()
+	timezone := time.FixedZone("Timezone", int(utils.GetServerTimezoneOffsetMinutes())*60)
 	thisYearFirstDatetime := time.Date(now.Year(), 1, 1, 0, 0, 0, 0, time.Local)
 	lastYearLastDatetime := thisYearFirstDatetime.Add(-1 * time.Second)
 	thisYearLastDatetime := lastYearLastDatetime.Add(24 * time.Hour)
 
-	assert.Equal(t, true, user.CanEditTransactionByTransactionTime(utils.GetMinTransactionTimeFromUnixTime(thisYearFirstDatetime.Unix()), utils.GetServerTimezoneOffsetMinutes()))
+	assert.Equal(t, true, user.CanEditTransactionByTransactionTime(utils.GetMinTransactionTimeFromUnixTime(thisYearFirstDatetime.Unix()), timezone))
-	assert.Equal(t, true, user.CanEditTransactionByTransactionTime(utils.GetMinTransactionTimeFromUnixTime(thisYearLastDatetime.Unix()), utils.GetServerTimezoneOffsetMinutes()))
+	assert.Equal(t, true, user.CanEditTransactionByTransactionTime(utils.GetMinTransactionTimeFromUnixTime(thisYearLastDatetime.Unix()), timezone))
-	assert.Equal(t, false, user.CanEditTransactionByTransactionTime(utils.GetMinTransactionTimeFromUnixTime(lastYearLastDatetime.Unix()), utils.GetServerTimezoneOffsetMinutes()))
+	assert.Equal(t, false, user.CanEditTransactionByTransactionTime(utils.GetMinTransactionTimeFromUnixTime(lastYearLastDatetime.Unix()), timezone))
 }

pkg/services/transactions.go

@@ -198,12 +198,11 @@ func (s *TransactionService) GetAllTransactionsInOneAccountWithAccountBalanceByM
 }
 
 // GetAllAccountsDailyOpeningAndClosingBalance returns daily opening and closing balance of all accounts within time range
-func (s *TransactionService) GetAllAccountsDailyOpeningAndClosingBalance(c core.Context, uid int64, maxTransactionTime int64, minTransactionTime int64, utcOffset int16) (map[int32][]*models.TransactionWithAccountBalance, error) {
+func (s *TransactionService) GetAllAccountsDailyOpeningAndClosingBalance(c core.Context, uid int64, maxTransactionTime int64, minTransactionTime int64, clientTimezone *time.Location) (map[int32][]*models.TransactionWithAccountBalance, error) {
 	if maxTransactionTime <= 0 {
 		maxTransactionTime = utils.GetMaxTransactionTimeFromUnixTime(time.Now().Unix())
 	}
 
-	clientLocation := time.FixedZone("Client Timezone", int(utcOffset)*60)
 	var allTransactions []*models.Transaction
 
 	for maxTransactionTime > 0 {
@@ -260,7 +259,7 @@ func (s *TransactionService) GetAllAccountsDailyOpeningAndClosingBalance(c core.
 			continue
 		}
 
-		yearMonthDay := utils.FormatUnixTimeToNumericYearMonthDay(utils.GetUnixTimeFromTransactionTime(transaction.TransactionTime), clientLocation)
+		yearMonthDay := utils.FormatUnixTimeToNumericYearMonthDay(utils.GetUnixTimeFromTransactionTime(transaction.TransactionTime), clientTimezone)
 		groupKey := fmt.Sprintf("%d_%d", yearMonthDay, transaction.AccountId)
 		dailyAccountBalance, exists := accountDailyLastBalances[groupKey]
 
@@ -284,7 +283,7 @@ func (s *TransactionService) GetAllAccountsDailyOpeningAndClosingBalance(c core.
 		firstTransactionTime = minTransactionTime
 	}
 
-	firstYearMonthDay := utils.FormatUnixTimeToNumericYearMonthDay(utils.GetUnixTimeFromTransactionTime(firstTransactionTime), clientLocation)
+	firstYearMonthDay := utils.FormatUnixTimeToNumericYearMonthDay(utils.GetUnixTimeFromTransactionTime(firstTransactionTime), clientTimezone)
 
 	// fill in the opening balance for accounts that do not have transactions on the first day
 	for accountId, accumulatedBalance := range accumulatedBalancesBeforeStartTime {
@@ -1798,14 +1797,13 @@ func (s *TransactionService) GetRelatedTransferTransaction(originalTransaction *
 }
 
 // GetAccountsTotalIncomeAndExpense returns the every accounts total income and expense amount by specific date range
-func (s *TransactionService) GetAccountsTotalIncomeAndExpense(c core.Context, uid int64, startUnixTime int64, endUnixTime int64, excludeAccountIds []int64, excludeCategoryIds []int64, utcOffset int16, useTransactionTimezone bool) (map[int64]int64, map[int64]int64, error) {
+func (s *TransactionService) GetAccountsTotalIncomeAndExpense(c core.Context, uid int64, startUnixTime int64, endUnixTime int64, excludeAccountIds []int64, excludeCategoryIds []int64, utcOffset int16, clientTimezone *time.Location, useTransactionTimezone bool) (map[int64]int64, map[int64]int64, error) {
 	if uid <= 0 {
 		return nil, nil, errs.ErrUserIdInvalid
 	}
 
-	clientLocation := time.FixedZone("Client Timezone", int(utcOffset)*60)
+	startLocalDateTime := utils.FormatUnixTimeToNumericLocalDateTime(startUnixTime, clientTimezone)
-	startLocalDateTime := utils.FormatUnixTimeToNumericLocalDateTime(startUnixTime, clientLocation)
+	endLocalDateTime := utils.FormatUnixTimeToNumericLocalDateTime(endUnixTime, clientTimezone)
-	endLocalDateTime := utils.FormatUnixTimeToNumericLocalDateTime(endUnixTime, clientLocation)
 
 	startUnixTime = utils.GetMinUnixTimeWithSameLocalDateTime(startUnixTime, utcOffset)
 	endUnixTime = utils.GetMaxUnixTimeWithSameLocalDateTime(endUnixTime, utcOffset)
@@ -1889,7 +1887,7 @@ func (s *TransactionService) GetAccountsTotalIncomeAndExpense(c core.Context, ui
 
 	for i := 0; i < len(allTransactions); i++ {
 		transaction := allTransactions[i]
-		timeZone := clientLocation
+		timeZone := clientTimezone
 
 		if useTransactionTimezone {
 			timeZone = time.FixedZone("Transaction Timezone", int(transaction.TimezoneUtcOffset)*60)
@@ -1923,22 +1921,21 @@ func (s *TransactionService) GetAccountsTotalIncomeAndExpense(c core.Context, ui
 }
 
 // GetAccountsAndCategoriesTotalInflowAndOutflow returns the every accounts and categories total inflows and outflows amount by specific date range
-func (s *TransactionService) GetAccountsAndCategoriesTotalInflowAndOutflow(c core.Context, uid int64, startUnixTime int64, endUnixTime int64, tagFilters []*models.TransactionTagFilter, noTags bool, keyword string, utcOffset int16, useTransactionTimezone bool) ([]*models.Transaction, error) {
+func (s *TransactionService) GetAccountsAndCategoriesTotalInflowAndOutflow(c core.Context, uid int64, startUnixTime int64, endUnixTime int64, tagFilters []*models.TransactionTagFilter, noTags bool, keyword string, utcOffset int16, clientTimezone *time.Location, useTransactionTimezone bool) ([]*models.Transaction, error) {
 	if uid <= 0 {
 		return nil, errs.ErrUserIdInvalid
 	}
 
-	clientLocation := time.FixedZone("Client Timezone", int(utcOffset)*60)
 	var startLocalDateTime, endLocalDateTime, startTransactionTime, endTransactionTime int64
 
 	if startUnixTime > 0 {
-		startLocalDateTime = utils.FormatUnixTimeToNumericLocalDateTime(startUnixTime, clientLocation)
+		startLocalDateTime = utils.FormatUnixTimeToNumericLocalDateTime(startUnixTime, clientTimezone)
 		startUnixTime = utils.GetMinUnixTimeWithSameLocalDateTime(startUnixTime, utcOffset)
 		startTransactionTime = utils.GetMinTransactionTimeFromUnixTime(startUnixTime)
 	}
 
 	if endUnixTime > 0 {
-		endLocalDateTime = utils.FormatUnixTimeToNumericLocalDateTime(endUnixTime, clientLocation)
+		endLocalDateTime = utils.FormatUnixTimeToNumericLocalDateTime(endUnixTime, clientTimezone)
 		endUnixTime = utils.GetMaxUnixTimeWithSameLocalDateTime(endUnixTime, utcOffset)
 		endTransactionTime = utils.GetMaxTransactionTimeFromUnixTime(endUnixTime)
 	}
@@ -2001,7 +1998,7 @@ func (s *TransactionService) GetAccountsAndCategoriesTotalInflowAndOutflow(c cor
 
 	for i := 0; i < len(allTransactions); i++ {
 		transaction := allTransactions[i]
-		timeZone := clientLocation
+		timeZone := clientTimezone
 
 		if useTransactionTimezone {
 			timeZone = time.FixedZone("Transaction Timezone", int(transaction.TimezoneUtcOffset)*60)
@@ -2046,12 +2043,11 @@ func (s *TransactionService) GetAccountsAndCategoriesTotalInflowAndOutflow(c cor
 }
 
 // GetAccountsAndCategoriesMonthlyInflowAndOutflow returns the every accounts monthly inflows and outflows amount by specific date range
-func (s *TransactionService) GetAccountsAndCategoriesMonthlyInflowAndOutflow(c core.Context, uid int64, startYear int32, startMonth int32, endYear int32, endMonth int32, tagFilters []*models.TransactionTagFilter, noTags bool, keyword string, utcOffset int16, useTransactionTimezone bool) (map[int32][]*models.Transaction, error) {
+func (s *TransactionService) GetAccountsAndCategoriesMonthlyInflowAndOutflow(c core.Context, uid int64, startYear int32, startMonth int32, endYear int32, endMonth int32, tagFilters []*models.TransactionTagFilter, noTags bool, keyword string, clientTimezone *time.Location, useTransactionTimezone bool) (map[int32][]*models.Transaction, error) {
 	if uid <= 0 {
 		return nil, errs.ErrUserIdInvalid
 	}
 
-	clientLocation := time.FixedZone("Client Timezone", int(utcOffset)*60)
 	var startTransactionTime, endTransactionTime int64
 	var err error
 
@@ -2132,7 +2128,7 @@ func (s *TransactionService) GetAccountsAndCategoriesMonthlyInflowAndOutflow(c c
 
 	for i := 0; i < len(allTransactions); i++ {
 		transaction := allTransactions[i]
-		timeZone := clientLocation
+		timeZone := clientTimezone
 
 		if useTransactionTimezone {
 			timeZone = time.FixedZone("Transaction Timezone", int(transaction.TimezoneUtcOffset)*60)

src/lib/datetime.ts

@@ -521,6 +521,10 @@ export function getBrowserTimezoneOffsetMinutes(): number {
     return -new Date().getTimezoneOffset();
 }
 
+export function guessTimezoneName(): string {
+    return moment.tz.guess(true);
+}
+
 export function getLocalDatetimeFromUnixTime(unixTime: number): Date {
     return new Date(unixTime * 1000);
 }

src/lib/services.ts

@@ -167,13 +167,19 @@ import {
     isBoolean,
     objectFieldWithValueToArrayItem
 } from './common.ts';
+import {
+    getTimeZone
+} from './settings.ts';
 import {
     getGoogleMapAPIKey,
     getBaiduMapAK,
     getAmapApplicationKey,
     getExchangeRatesRequestTimeout
 } from './server_settings.ts';
-import { getTimezoneOffsetMinutes } from './datetime.ts';
+import {
+    getTimezoneOffsetMinutes,
+    guessTimezoneName
+} from './datetime.ts';
 import { generateRandomUUID } from './misc.ts';
 import { getBasePath } from './web.ts';
 import logger from './logger.ts';
@@ -204,6 +210,14 @@ axios.interceptors.request.use((config: ApiRequestConfig) => {
 
     config.headers['X-Timezone-Offset'] = getTimezoneOffsetMinutes();
 
+    let timezoneName = getTimeZone();
+
+    if (!timezoneName || timezoneName.trim().length < 1) {
+        timezoneName = guessTimezoneName();
+    }
+
+    config.headers['X-Timezone-Name'] = timezoneName;
+
     if (needBlockRequest && !config.ignoreBlocked) {
         return new Promise(resolve => {
             blockedRequests.push(newToken => {

src/lib/settings.ts

@@ -89,6 +89,10 @@ export function getTheme(): string {
     return getApplicationSettings().theme;
 }
 
+export function getTimeZone(): string {
+    return getApplicationSettings().timeZone;
+}
+
 export function isEnableApplicationLock(): boolean {
     return getApplicationSettings().applicationLock;
 }

src/locales/helpers.ts

@@ -202,6 +202,7 @@ import {
     getTimeDifferenceHoursAndMinutes,
     getTimezoneOffset,
     getTimezoneOffsetMinutes,
+    guessTimezoneName,
     isDateRangeMatchFullMonths,
     isDateRangeMatchFullYears,
     isPM
@@ -2316,7 +2317,7 @@ export function useI18n() {
             logger.info(`Current timezone is ${timezone}`);
             setTimeZone(timezone);
         } else {
-            logger.info(`No timezone is set, use browser default ${getTimezoneOffset()} (maybe ${moment.tz.guess(true)})`);
+            logger.info(`No timezone is set, use browser default ${getTimezoneOffset()} (maybe ${guessTimezoneName()})`);
             setTimeZone('');
         }