Do you have one or more mailboxes running in a wrong TimeZone on your Office 365 or Exchange environment? Don’t worry it is easy to fix, and I will show you how do to it. Follow this blog post and you will learn how to see current TimeZone on a mailbox, how to change it, and how to changes TimeZone on all mailboxes.

See current TimeZone on a mailbox
To see current TimeZone on a mailbox, simply use this command.

Change TimeZone on one mailbox

To change the TimeZone on a mailbox we need to use Set-MailboxRegionalConfiguration like below.

Change TimeZone on all mailboxes

You can use following PowerShell command to change the TimeZone on all mailboxes.


Not sure which TimeZone to use? Please see the TimeZone tabel on Microsoft’s website (