How to set OWA Language and Time zone using PowerShell

When a user first logs on to Outlook Web App (OWA), he/she gets prompted to set their language and time zone:

 

Can we, as administrators, pre-set these for users or change them after they have been set, for example? Of course! To do this, we use the Get/Set-MailboxRegionalConfiguration cmdlet:

The two parameters we are interested for this scenario are:

• Language: specifies the language setting, such as en-us, that would apply for the mailbox;
• TimeZone: specifies the time zone, such as Pacific Standard Time, that the mailbox in the specified region uses. The default value is the time zone setting on the server.

Let us say, for example, that we want to set everyone’s mailbox to American English and Pacific time. To do this, all we need to run is:

Get-Mailbox –ResultSize Unlimited –Filter {RecipientTypeDetails –eq "UserMailbox"} | Set-MailboxRegionalConfiguration –Language en-US –TimeZone "Pacific Standard
Time"