How to Change Time Zone settings in an Exchange Server and its User mailboxes in Exchange 2010/2013/2016/Online

 Thank to: https://www.azure365pro.com/

Lets see how to Change time zone in Exchange Server. lets say an old Admin built the server with the wrong time zone and And now after some years. people found that meetings received showing in a different Time zone.  how to change it ?

Step 1:

Go to your system Clock and change it

View Time Zone settings for a specified user

Get-MailboxRegionalConfiguration "Adam_Bokiniec"

Reset Time Zone settings for a specific user, this will let the user to choose his own Time Zone settings with next Outlook Web App (OWA) login

Set-Mailbox -Identity "Adam_Bokiniec" -Languages $null

Reset Time Zone settings for all users

Get-Mailbox | Set-Mailbox -Languages $null

Set the Time Zone setting for a specified user, to identify the correct syntax for “TimeZone” parameter set the Time Zone” for a user in the OWA and use “Get-MailboxRegionalConfiguration”.

Set-MailboxRegionalConfiguration -Identity "Adam_Bokiniec" -Language en-GB -DateFormat "dd/MM/yyyy" -TimeFormat "HH:mm" -TimeZone "W. Europe Standard Time"

Set the Time Zone settings for all users

Get-Mailbox | Set-MailboxRegionalConfiguration -Language en-GB -DateFormat "dd/MM/yyyy" -TimeFormat "HH:mm" -TimeZone "W. Europe Standard Time"

Set the Time Zone settings for specified OU

Get-Mailbox -OrganizationalUnit "careexchange.in/Users” | Set-MailboxRegionalConfiguration -Language en-GB -DateFormat "dd/MM/yyyy" -TimeFormat "HH:mm" -TimeZone "W. Europe Standard Time"

Set default client language for Outlook Web App (OWA) for all users, here you need to use Language Codes witch can be found here: http://technet.microsoft.com/en-us/library/aa997435.aspx. Once the default client language is specified when the users try to login for the first time in OWA, they are not prompted to choose a language and OWA Time Zone is picked up from the time zone of Client Access Server.

Set-OWAVirtualDirectory “OWA (Default Web Site)” -DefaultClientLanguage 2057