• Mission: change regional settings for a user (or many) mailbox(es)

• Symptoms
  • Messages received by an user are being displayed with a different timestamp of the user (for instance: user time zone is UTC-5 but messages are being displayed UTC)
    • OR
  • You want to standardize exchange regional settings for multiple users

• Prerequisites
  • Have ExchangePowershell module installed
    • Install-Module Exchange Powershell
  • Connect to exchange via powershell before running the commands
    • Run Powershell
    • Type Connect-ExchangeOnline
    • A “Sign in to your account” iteractive box will pop-up. Enter the Exchange Id with enough permissions to write/modify settings

To modify the parameters for a single account run the following command

Set-MailboxRegionalConfiguration -Identity "[User_Mail_address]" -Language "[Language]" -DateFormat "[DateFormat]" -TimeFormat "TimeFormat" -TimeZone "TimeZone" 

Example: Set the parameters for user user@techmission.ca

Set-MailboxRegionalConfiguration -Identity user@techmission.ca -Language "en-CA" -DateFormat "yyyy-MM-dd" -TimeFormat "h:mm tt" -TimeZone "Atlantic Standard Time"

You can choose as many parameters as you want (for instance if you want to set only the time zone: Set-MailboxRegionalConfiguration -Identity user@techmission.ca -TimeZone “Atlantic Standard Time”)

For multiple accounts you need to populate a variable and run it in a foreach. If we go oneliner it is something like this:

Get-Mailbox | ? { $_.[the_param_you_want] -match "[the_results_you_want]"}| % { Set-MailboxRegionalConfiguration -Identity $_.UserPrincipalName -Language "en-CA" -DateFormat "yyyy-MM-dd" -TimeFormat "h:mm tt" -TimeZone "Atlantic Standard Time" }

Example: Set the parameters for all users where theirs UserPrincipalNames contains the sub-domain timezone.techmission.ca

Get-Mailbox | ? { $_.UserPrincipalName -match "@timezone.techmission.ca"}| % { Set-MailboxRegionalConfiguration -Identity $_.UserPrincipalName -Language "en-CA" -DateFormat "yyyy-MM-dd" -TimeFormat "h:mm tt" -TimeZone "Atlantic Standard Time" }

You can find the cmdlet description and parameters following this link Set-MailboxRegionalConfiguration (ExchangePowerShell) | Microsoft Learn