New projects should have their timezone set when they were created. If you did not do this, or want to change the timezone, please follow these instructions.
The time zone must be set in the "Project Settings" page in order for the project reports to show in the correct time. You can access the project settings by clicking on the gear icon in the upper right-hand corner of the screen or by selecting Settings from the Dashboard:
This will bring you to your project settings page. You must be an admin in order to do this.
Basic Timezone Setting
You can use the dropdown menu or start typing the name of a location to find the appropriate time zone. This will become the time zone used in reporting for the project by default. Note that this not apply to some of the more specialized reports such as "Application Status"; however it is true for all of the worker monitoring reports.
Make sure to click on "Update Basic Info" button to save your changes.
Web User-Specific Timezone Settings
Individual web users, however, can see the project reports in a different time zone if they prefer. These settings can be accessed in the Project Settings screen.
If you check the box next to "Override project's timezone setting" you will see an option to display a different time zone. In the screen shot above, the project timezone is set to use Asia/Kolkata time, but the user wants to see the reporting in Africa/Nairobi time. To select "My Timezone" you will need to scroll through the dropdown until you find your preferred timezone. Clicking on "Reset to Default" will reset the user-specific timezone to the project timezone. Make sure to click "Update My Settings" when you are done.
Changing "My Timezone" will only affect how you see the project space you are working in.
How to handle project spaces with multiple countries
Each web user on the project may set their own preferred timezone that overrides the project timezone when they're looking at reports. If the same user wanted to see India data in IST and South America data in the correct South American timezone, then they would have to change their own preferred timezone override between looking at one location's data and looking at the other. If there are certain people who only look at India data or only look at South America data then this could be helpful for them
When you export data to excel, date/times will always be in UTC / +00:00 timezone / "zulu time", regardless of the project's timezone. It was decided to do this for exactly this reason: if you have different timezones at play, then as much as a pain as it is, it's still much easier if everything is consistently reported in this standard time than if it's unclear which timezone a particular date/time is in.
Dates and Times Calculated Within a Form
When a date or time is calculated within a form in your application, the timezone used will be based on the browser's (WebApps) or phone's (mobile) timezone settings, not the project space's timezone settings. For more information on the date and time functions available within CommCare forms, refer to the CommCare Functions wiki and the Calculations with Dates and Times wiki.