add getting timezone offset method

pkg/utils/datetimes.go

@@ -59,10 +59,17 @@ func ParseFromShortDateTime(t string, utcOffset int16) (time.Time, error) {
 	return time.ParseInLocation(shortDateTimeFormat, t, timezone)
 }
 
+// GetTimezoneOffsetMinutes returns offset minutes according specified timezone
+func GetTimezoneOffsetMinutes(timezone *time.Location) int16 {
+	_, tzOffset := time.Now().In(timezone).Zone()
+	tzMinuteOffset := int16(tzOffset / 60)
+
+	return tzMinuteOffset
+}
+
 // FormatTimezoneOffset returns "+/-HH:MM" format of timezone
 func FormatTimezoneOffset(timezone *time.Location) string {
-	_, tzOffset := time.Now().In(timezone).Zone()
-	tzMinutesOffset := tzOffset / 60
+	tzMinutesOffset := GetTimezoneOffsetMinutes(timezone)
 
 	sign := "+"
 	hourAbsOffset := tzMinutesOffset / 60

pkg/utils/datetimes_test.go

@@ -53,6 +53,28 @@ func TestParseFromShortDateTime(t *testing.T) {
 	assert.Equal(t, expectedValue, actualValue)
 }
 
+func TestGetTimezoneOffsetMinutes(t *testing.T) {
+	timezone := time.FixedZone("Test Timezone", 120*60)
+	expectedValue := int16(120)
+	actualValue := GetTimezoneOffsetMinutes(timezone)
+	assert.Equal(t, expectedValue, actualValue)
+
+	timezone = time.FixedZone("Test Timezone", 345*60)
+	expectedValue = int16(345)
+	actualValue = GetTimezoneOffsetMinutes(timezone)
+	assert.Equal(t, expectedValue, actualValue)
+
+	timezone = time.FixedZone("Test Timezone", -720*60)
+	expectedValue = int16(-720)
+	actualValue = GetTimezoneOffsetMinutes(timezone)
+	assert.Equal(t, expectedValue, actualValue)
+
+	timezone = time.FixedZone("Test Timezone", 0)
+	expectedValue = int16(0)
+	actualValue = GetTimezoneOffsetMinutes(timezone)
+	assert.Equal(t, expectedValue, actualValue)
+}
+
 func TestFormatTimezoneOffset(t *testing.T) {
 	timezone := time.FixedZone("Test Timezone", 120*60)
 	expectedValue := "+02:00"