From c8d264af88051b89be381a513f7ef2c78b604f80 Mon Sep 17 00:00:00 2001
From: Eddasol <esole@equinor.com>
Date: Fri, 12 Apr 2024 16:22:45 +0200
Subject: [PATCH] Fix mix between UTC and local time

---
 .../HistoricMissionCard.tsx                   |  2 +-
 .../MissionHeader/MissionHeader.tsx           | 20 +++++++++++--------
 frontend/src/utils/StringFormatting.tsx       | 11 +++++++---
 3 files changed, 21 insertions(+), 12 deletions(-)

diff --git a/frontend/src/components/Pages/MissionHistoryPage/HistoricMissionCard.tsx b/frontend/src/components/Pages/MissionHistoryPage/HistoricMissionCard.tsx
index 10860accf..aa175e41f 100644
--- a/frontend/src/components/Pages/MissionHistoryPage/HistoricMissionCard.tsx
+++ b/frontend/src/components/Pages/MissionHistoryPage/HistoricMissionCard.tsx
@@ -33,7 +33,7 @@ const MissionEndTimeDisplay = ({ mission }: MissionProps) => {
     return (
         <>
             {mission.endTime ? (
-                <Typography>{formatDateTime(new Date(mission.endTime), 'HH:mm:ss - dd/MM/yy')}</Typography>
+                <Typography>{formatDateTime(mission.endTime, 'HH:mm:ss - dd/MM/yy')}</Typography>
             ) : (
                 <Typography>-</Typography>
             )}
diff --git a/frontend/src/components/Pages/MissionPage/MissionHeader/MissionHeader.tsx b/frontend/src/components/Pages/MissionPage/MissionHeader/MissionHeader.tsx
index c77038003..8c0194675 100644
--- a/frontend/src/components/Pages/MissionPage/MissionHeader/MissionHeader.tsx
+++ b/frontend/src/components/Pages/MissionPage/MissionHeader/MissionHeader.tsx
@@ -97,19 +97,23 @@ const getStartUsedAndRemainingTime = (
 
     if (mission.endTime) {
         startTime = mission.startTime
-            ? formatDateTime(new Date(mission.startTime), 'HH:mm')
-            : formatDateTime(new Date(mission.endTime), 'HH:mm')
+            ? formatDateTime(mission.startTime, 'HH:mm')
+            : formatDateTime(mission.endTime, 'HH:mm')
+
         startDate = mission.startTime
-            ? formatDateTime(new Date(mission.startTime), 'dd/MM/yyy')
-            : formatDateTime(new Date(mission.endTime), 'dd/MM/yyy')
+            ? formatDateTime(mission.startTime, 'dd/MM/yyy')
+            : formatDateTime(mission.endTime, 'dd/MM/yyy')
         usedTimeInMinutes = mission.startTime
-            ? differenceInMinutes(new Date(mission.endTime), new Date(mission.startTime))
+            ? differenceInMinutes(
+                  convertUTCDateToLocalDate(mission.endTime),
+                  convertUTCDateToLocalDate(mission.startTime)
+              )
             : 0
         remainingTime = 'N/A'
     } else if (mission.startTime) {
-        startTime = formatDateTime(new Date(mission.startTime), 'HH:mm')
-        startDate = formatDateTime(new Date(mission.startTime), 'dd/MM/yyy')
-        usedTimeInMinutes = differenceInMinutes(Date.now(), convertUTCDateToLocalDate(new Date(mission.startTime)))
+        startTime = formatDateTime(mission.startTime, 'HH:mm')
+        startDate = formatDateTime(mission.startTime, 'dd/MM/yyy')
+        usedTimeInMinutes = differenceInMinutes(Date.now(), convertUTCDateToLocalDate(mission.startTime))
         if (estimatedDurationInMinutes)
             remainingTime = Math.max(estimatedDurationInMinutes - usedTimeInMinutes, 0) + ' ' + translatedMinutes
         else remainingTime = 'N/A'
diff --git a/frontend/src/utils/StringFormatting.tsx b/frontend/src/utils/StringFormatting.tsx
index ef7137f29..6d7fabe8e 100644
--- a/frontend/src/utils/StringFormatting.tsx
+++ b/frontend/src/utils/StringFormatting.tsx
@@ -2,8 +2,13 @@ import { format } from 'date-fns'
 
 const millisecondsInADay = 8.64e7
 
-export const convertUTCDateToLocalDate = (date: Date): Date =>
-    new Date(date.getTime() - date.getTimezoneOffset() * 60 * 1000)
+export const convertUTCDateToLocalDate = (date: Date): Date => {
+    // If lastChar is Z, typescript assumes the date to be UTC
+    const lastChar = date.toString().slice(-1)
+    if (lastChar === 'Z') return new Date(date)
+    // If not, typescript assumes the date to be local time
+    return new Date(new Date(date).getTime() - new Date(date).getTimezoneOffset() * 60 * 1000)
+}
 
 const formatBackendDateTimeToDate = (date: Date) => new Date(date.toString())
 
@@ -30,4 +35,4 @@ export const getDeadlineInDays = (deadlineDate: Date): number =>
     new Date(deadlineDate.getTime() - new Date().getTime()).getTime() / millisecondsInADay
 
 export const formatDateTime = (dateTime: Date, dateFormat: string): string =>
-    format(convertUTCDateToLocalDate(new Date(dateTime)), dateFormat)
+    format(convertUTCDateToLocalDate(dateTime), dateFormat)