It is very important that the time zone settings on your phone correspond with your current region and time zone for that region. If the wrong time zone is applied you will receive the incorrect shift times on the calendar and roster in your app.
Time Zone Settings Android:
Navigate to Settings
2. Search Time in Settings
3. Select Date&Time
4. Check Automatic Time Zone. If this is already selected then simply make sure you have the correct time-zone allocated underneath.
5. If you have the incorrect time zone allocated or wish to change your time zone allocation manually then switch off Automatic Time Zone. This will enable you to choose your time zone
6. Select the region (country) you are currently working or living in
7. Select the appropriate time-zone for the city you are currently working in
Time Zone Settings Apple
To learn how to set-up the correct time zone on your Apple device read below Apple support menu.