Read Receipts showing wrong time or time zone for Office 365 mailbox

If you get read receipts that state the time it was read was the previous day, or the time is just wrong this could be to do with the time settings on the mailbox.

Microsoft have a poor guide on this explaining WHY it happens, but does not say how to resolve it. 

https://support.microsoft.com/en-gb/help/2800633/read-receipt-from-an-office-365-recipient-displays-incorrect-time-zone-information

Here is the solution:

We can check this by first connecting to Office 365 via Azure PowerShell, and then running the follwing command. 

Get-MailboxRegionalConfiguration -Identity [email protected] | fl

If the TimeZone is wrong, it will be obvious. You will need to change it to your users local time zone. To see a list of time zones run this command in PowerShell.

$TimeZone = Get-ChildItem "HKLM:SoftwareMicrosoftWindows NTCurrentVersionTime zones" | foreach {Get-ItemProperty $_.PSPath}; $TimeZone | sort Display | Format-Table -Auto PSChildname,Display

Once you know your time zone, run the following (replacing your correct time zone). 

Set-MailboxRegionalConfiguration -Identity [email protected] -TimeZone "GMT Standard Time"

https://technet.microsoft.com/en-us/library/dd351103(v=exchg.160).aspx