ensure user profile calendar is generated based on server timezone, not local timezone

app/assets/javascripts/users/activity_calendar.js

@@ -6,6 +6,14 @@ const LOADING_HTML = `
   </div>
 `;
+function getSystemDate(systemUtcOffsetSeconds) {
+  const date = new Date();
+  const localUtcOffsetMinutes = 0 - date.getTimezoneOffset();
+  const systemUtcOffsetMinutes = systemUtcOffsetSeconds / 60;
+  date.setMinutes((date.getMinutes() - localUtcOffsetMinutes) + systemUtcOffsetMinutes);
+  return date;
+}
+
 function formatTooltipText({ date, count }) {
   const dateObject = new Date(date);
   const dateDayName = gl.utils.getDayName(dateObject);
@@ -21,7 +29,7 @@ function formatTooltipText({ date, count }) {
 const initColorKey = () => d3.scale.linear().range(['#acd5f2', '#254e77']).domain([0, 3]);
 export default class ActivityCalendar {
-  constructor(container, timestamps, calendarActivitiesPath) {
+  constructor(container, timestamps, calendarActivitiesPath, utcOffset = 0) {
     this.calendarActivitiesPath = calendarActivitiesPath;
     this.clickDay = this.clickDay.bind(this);
     this.currentSelectedDate = '';
@@ -36,7 +44,7 @@ export default class ActivityCalendar {
     this.timestampsTmp = [];
     let group = 0;
-    const today = new Date();
+    const today = getSystemDate(utcOffset);
     today.setHours(0, 0, 0, 0, 0);
     const oneYearAgo = new Date(today);

app/assets/javascripts/users/user_tabs.js

@@ -150,6 +150,7 @@ export default class UserTabs {
     const $calendarWrap = this.$parentEl.find('.user-calendar');
     const calendarPath = $calendarWrap.data('calendarPath');
     const calendarActivitiesPath = $calendarWrap.data('calendarActivitiesPath');
+    const utcOffset = $calendarWrap.data('utcOffset');
     $.ajax({
       dataType: 'json',
@@ -158,7 +159,7 @@ export default class UserTabs {
         $calendarWrap.html(CALENDAR_TEMPLATE);
         // eslint-disable-next-line no-new
-        new ActivityCalendar('.js-contrib-calendar', activityData, calendarActivitiesPath);
+        new ActivityCalendar('.js-contrib-calendar', activityData, calendarActivitiesPath, utcOffset);
       },
     });

app/views/users/show.html.haml

@@ -104,7 +104,7 @@
     .tab-content
       #activity.tab-pane
         .row-content-block.calender-block.white.second-block.hidden-xs
-          .user-calendar{ data: { calendar_path: user_calendar_path(@user, :json), calendar_activities_path: user_calendar_activities_path } }
+          .user-calendar{ data: { calendar_path: user_calendar_path(@user, :json), calendar_activities_path: user_calendar_activities_path, utc_offset: Time.zone.utc_offset } }
             %h4.center.light
               %i.fa.fa-spinner.fa-spin
           .user-calendar-activities