The first time that you sign in to OWA (Outlook Web App), you will be asked to set your current time zone.

If you don't set the time zone, the time zone is set to (UTC) Monrovia, Reykjavik. There's no method for admins to set up the time zone setting in advance in Outlook Web App for all users.

The following screen shot shows the Outlook Web App sign-in screen in Office 365.

 

 To change the time zone to the correct setting in OWA (Outlook Web App), follow these steps:

  1. Sign in to Outlook Web App, click Settings (   ), and then click Options
  2. In the left navigation pane, click Settings, and then click Regional
  3. In the Current time zone box, click the arrow, and then click the correct time zone setting
  4. Click Save

For more information about how to set the time zone in Outlook Web App, see Regional settings