From 381085f6559bb7acc10cf333bcfd6d5a0d65a60a Mon Sep 17 00:00:00 2001
From: Scott Bishel <scott.bishel@mattermost.com>
Date: Thu, 4 Nov 2021 12:21:47 -0600
Subject: [PATCH] Fixes issue with dates and daylight savings (#1752)

* dates should use themselves for timezone offset

* remove log lines

Co-authored-by: Mattermod <mattermod@users.noreply.github.com>
---
 .../components/properties/dateRange/dateRange.tsx   | 13 ++++++++-----
 1 file changed, 8 insertions(+), 5 deletions(-)

diff --git a/webapp/src/components/properties/dateRange/dateRange.tsx b/webapp/src/components/properties/dateRange/dateRange.tsx
index 541c2f7c1..6e8a8b691 100644
--- a/webapp/src/components/properties/dateRange/dateRange.tsx
+++ b/webapp/src/components/properties/dateRange/dateRange.tsx
@@ -38,7 +38,6 @@ const loadedLocales: Record<string, moment.Locale> = {}
 function DateRange(props: Props): JSX.Element {
     const {className, value, showEmptyPlaceholder, onChange} = props
     const intl = useIntl()
-    const timeZoneOffset = new Date().getTimezoneOffset() * 60 * 1000
 
     const getDisplayDate = (date: Date | null | undefined) => {
         let displayDate = ''
@@ -48,6 +47,10 @@ function DateRange(props: Props): JSX.Element {
         return displayDate
     }
 
+    const timeZoneOffset = (date: number): number => {
+        return new Date(date).getTimezoneOffset() * 60 * 1000
+    }
+
     const createDatePropertyFromString = (initialValue: string) => {
         let dateProperty: DateProperty = {}
         if (initialValue) {
@@ -71,8 +74,8 @@ function DateRange(props: Props): JSX.Element {
     // Keep dateProperty as UTC,
     // dateFrom / dateTo will need converted to local time, to ensure date stays consistent
     // dateFrom / dateTo will be used for input and calendar dates
-    const dateFrom = dateProperty.from ? new Date(dateProperty.from + (dateProperty.includeTime ? 0 : timeZoneOffset)) : undefined
-    const dateTo = dateProperty.to ? new Date(dateProperty.to + (dateProperty.includeTime ? 0 : timeZoneOffset)) : undefined
+    const dateFrom = dateProperty.from ? new Date(dateProperty.from + (dateProperty.includeTime ? 0 : timeZoneOffset(dateProperty.from))) : undefined
+    const dateTo = dateProperty.to ? new Date(dateProperty.to + (dateProperty.includeTime ? 0 : timeZoneOffset(dateProperty.to))) : undefined
     const [fromInput, setFromInput] = useState<string>(getDisplayDate(dateFrom))
     const [toInput, setToInput] = useState<string>(getDisplayDate(dateTo))
 
@@ -118,10 +121,10 @@ function DateRange(props: Props): JSX.Element {
     const saveRangeValue = (range: DateProperty) => {
         const rangeUTC = {...range}
         if (rangeUTC.from) {
-            rangeUTC.from -= dateProperty.includeTime ? 0 : timeZoneOffset
+            rangeUTC.from -= dateProperty.includeTime ? 0 : timeZoneOffset(rangeUTC.from)
         }
         if (rangeUTC.to) {
-            rangeUTC.to -= dateProperty.includeTime ? 0 : timeZoneOffset
+            rangeUTC.to -= dateProperty.includeTime ? 0 : timeZoneOffset(rangeUTC.to)
         }
 
         setDateProperty(rangeUTC)