use the daylight saving time zone as default time zone rather than the current standard time zone during the DST

src/components/mobile/DateRangeSelectionSheet.vue

@@ -45,13 +45,6 @@ import { type CommonDateRangeSelectionProps, useDateRangeSelectionBase } from '@
 
 import { useEnvironmentsStore } from '@/stores/environment.ts';
 
-import {
-    getLocalDatetimeFromUnixTime,
-    getDummyUnixTimeForLocalUsage,
-    getTimezoneOffsetMinutes,
-    getBrowserTimezoneOffsetMinutes
-} from '@/lib/datetime.ts';
-
 type DateTimePickerType = InstanceType<typeof DateTimePicker>;
 
 const props = defineProps<CommonDateRangeSelectionProps>();
@@ -62,7 +55,14 @@ const emit = defineEmits<{
 
 const { tt } = useI18n();
 const { showToast } = useI18nUIComponents();
-const { dateRange, beginDateTime, endDateTime, presetRanges, getFinalDateRange } = useDateRangeSelectionBase(props);
+const {
+    dateRange,
+    beginDateTime,
+    endDateTime,
+    presetRanges,
+    getLocalDatetimeFromSameDateTimeOfUnixTime,
+    getFinalDateRange
+} = useDateRangeSelectionBase(props);
 
 const environmentsStore = useEnvironmentsStore();
 
@@ -91,11 +91,11 @@ function cancel(): void {
 
 function onSheetOpen(): void {
     if (props.minTime) {
-        dateRange.value[0] = getLocalDatetimeFromUnixTime(getDummyUnixTimeForLocalUsage(props.minTime, getTimezoneOffsetMinutes(), getBrowserTimezoneOffsetMinutes()));
+        dateRange.value[0] = getLocalDatetimeFromSameDateTimeOfUnixTime(props.minTime);
     }
 
     if (props.maxTime) {
-        dateRange.value[1] = getLocalDatetimeFromUnixTime(getDummyUnixTimeForLocalUsage(props.maxTime, getTimezoneOffsetMinutes(), getBrowserTimezoneOffsetMinutes()));
+        dateRange.value[1] = getLocalDatetimeFromSameDateTimeOfUnixTime(props.maxTime);
     }
 
     window.dispatchEvent(new Event('resize')); // fix vue-datepicker preset max-width

src/components/mobile/DateTimeSelectionSheet.vue

@@ -111,9 +111,7 @@ import { NumeralSystem } from '@/core/numeral.ts';
 import { isDefined } from '@/lib/common.ts';
 import {
     getHourIn12HourFormat,
-    getLocalDatetimeFromUnixTime,
     getCurrentUnixTime,
-    getUnixTimeFromLocalDatetime,
     getAMOrPM,
     getCombinedDateAndTimeValues
 } from '@/lib/datetime.ts';
@@ -122,6 +120,7 @@ type DateTimePickerType = InstanceType<typeof DateTimePicker>;
 
 const props = defineProps<{
     modelValue: number;
+    timezoneUtcOffset: number;
     initMode?: string;
     show: boolean;
 }>();
@@ -144,6 +143,8 @@ const {
     isSecondTwoDigits,
     isMeridiemIndicatorFirst,
     meridiemItems,
+    getLocalDatetimeFromSameDateTimeOfUnixTime,
+    getUnixTimeFromSameDateTimeOfLocalDatetime,
     getDisplayTimeValue,
     generateAllHours,
     generateAllMinutesOrSeconds
@@ -160,7 +161,7 @@ let resetTimePickerItemPositionItemsLastOffsetTop: number | undefined = undefine
 let resetTimePickerItemPositionCheckedFrames: number | undefined = undefined;
 
 const mode = ref<string>(props.initMode || 'time');
-const dateTime = ref<Date>(getLocalDatetimeFromUnixTime(props.modelValue || getCurrentUnixTime()));
+const dateTime = ref<Date>(getLocalDatetimeFromSameDateTimeOfUnixTime(props.modelValue || getCurrentUnixTime(), props.timezoneUtcOffset));
 const timePickerContainerHeight = ref<number | undefined>(undefined);
 const timePickerItemHeight = ref<number | undefined>(undefined);
 
@@ -213,7 +214,7 @@ function switchMode(): void {
 }
 
 function setCurrentTime(): void {
-    dateTime.value = getLocalDatetimeFromUnixTime(getCurrentUnixTime());
+    dateTime.value = getLocalDatetimeFromSameDateTimeOfUnixTime(getCurrentUnixTime(), props.timezoneUtcOffset);
 
     if (mode.value === 'time') {
         scrollAllTimeSelectedItems();
@@ -225,7 +226,7 @@ function confirm(): void {
         return;
     }
 
-    const unixTime = getUnixTimeFromLocalDatetime(dateTime.value);
+    const unixTime = getUnixTimeFromSameDateTimeOfLocalDatetime(dateTime.value, props.timezoneUtcOffset);
 
     if (unixTime < 0) {
         showToast('Date is too early');
@@ -420,7 +421,7 @@ function onSheetOpen(): void {
     mode.value = props.initMode || 'time';
 
     if (props.modelValue) {
-        dateTime.value = getLocalDatetimeFromUnixTime(props.modelValue);
+        dateTime.value = getLocalDatetimeFromSameDateTimeOfUnixTime(props.modelValue, props.timezoneUtcOffset);
     }
 
     if (mode.value === 'time') {

src/components/mobile/TrendsBarChart.vue

@@ -144,6 +144,7 @@ import {
     isNumber
 } from '@/lib/common.ts';
 import {
+    parseDateTimeFromUnixTime,
     getYearMonthFirstUnixTime,
     getYearMonthLastUnixTime,
     getDateTypeByDateRange,
@@ -200,11 +201,11 @@ const emit = defineEmits<{
 
 const {
     tt,
-    formatUnixTimeToShortDate,
-    formatUnixTimeToGregorianLikeShortYear,
-    formatUnixTimeToGregorianLikeShortYearMonth,
+    formatDateTimeToShortDate,
+    formatDateTimeToGregorianLikeShortYear,
+    formatDateTimeToGregorianLikeShortYearMonth,
     formatYearQuarterToGregorianLikeYearQuarter,
-    formatUnixTimeToGregorianLikeFiscalYear,
+    formatDateTimeToGregorianLikeFiscalYear,
     formatAmountToLocalizedNumeralsWithCurrency
 } = useI18n();
 
@@ -324,18 +325,19 @@ const allDisplayDataItems = computed<TrendsBarChartData>(() => {
             dateRangeKey = `${dateRange.year}-${dateRange.month}-${dateRange.day}`;
         }
 
+        const minDateTime = parseDateTimeFromUnixTime(dateRange.minUnixTime);
         let displayDateRange = '';
 
         if (props.dateAggregationType === ChartDateAggregationType.Year.type) {
-            displayDateRange = formatUnixTimeToGregorianLikeShortYear(dateRange.minUnixTime);
+            displayDateRange = formatDateTimeToGregorianLikeShortYear(minDateTime);
         } else if (props.dateAggregationType === ChartDateAggregationType.FiscalYear.type) {
-            displayDateRange = formatUnixTimeToGregorianLikeFiscalYear(dateRange.minUnixTime);
+            displayDateRange = formatDateTimeToGregorianLikeFiscalYear(minDateTime);
         } else if (props.dateAggregationType === ChartDateAggregationType.Quarter.type && 'quarter' in dateRange) {
             displayDateRange = formatYearQuarterToGregorianLikeYearQuarter(dateRange.year, dateRange.quarter);
         } else if (props.dateAggregationType === ChartDateAggregationType.Month.type) {
-            displayDateRange = formatUnixTimeToGregorianLikeShortYearMonth(dateRange.minUnixTime);
+            displayDateRange = formatDateTimeToGregorianLikeShortYearMonth(minDateTime);
         } else if (props.dateAggregationType === ChartDateAggregationType.Day.type && props.chartMode === 'daily') {
-            displayDateRange = formatUnixTimeToShortDate(dateRange.minUnixTime);
+            displayDateRange = formatDateTimeToShortDate(minDateTime);
         }
 
         const dataItems = allDateRangeItemsMap[dateRangeKey] || [];