Wrong time generated by MS Outlook

Hi Bourbon,

It sounds like Outlook.com may be using a different time zone when formatting the forwarded or copied message header than the one shown in your display settings. This can occur if the mailbox time zone setting does not fully refresh.

To force a refresh of the time zone setting in Outlook.com (web), try the following:

1. Refresh the mailbox time zone

• ⚙️ Settings > General > Language and time
• Even if it already shows Eastern, temporarily select a different time zone and Save
• Change it back to (UTC‑05:00) Eastern Time (US & Canada) and Save again

2. Verify Calendar time zone

• Go to Calendar > View
• Confirm the time zone is also set to Eastern and save any changes

3. Sign out and test

• Sign out of Outlook.com
• Close the browser, then sign back in (You can also test in an InPrivate/Incognito window to rule out cached settings.)

Note: During Daylight Saving Time, Eastern Time uses UTC‑4; during standard time, it uses UTC‑5.

If the time is still incorrect after this, please copy and paste the Date: line from the message’s Internet headers (View > Message details). That will help confirm which time zone offset the server is applying when the message is generated.

Please let me know if this proves useful to you, or if you would like further assistance.

I'm looking forward to your reply.

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Eastern Standard time is incorrectly set on Outlook.com server as GMT = 0000.

The Proper setting should be GMT - 5 hours

The message header time is controlled by time zone settings on the mailbox/server and in Outlook, not by the text of the header itself. When the header shows GMT+5 instead of the expected GMT−5 for Eastern Time, the mailbox or web client is using the wrong time zone.

Use these steps depending on where the issue appears:

1. Verify Windows and Outlook time zone (classic Outlook desktop)
   • Make sure Windows is set to (UTC−05:00) Eastern Time (US & Canada) and that Automatically adjust clock for Daylight Saving Time is enabled.
   • In Windows: open Date and Time → Change time zone → confirm the time zone and check Automatically adjust clock for Daylight Saving Time.
   • Outlook desktop uses the Windows time zone, so a mismatch here causes wrong times in Outlook.
2. Fix time zone in Outlook on the web / Outlook.com
   • Sign in to Outlook on the web / Outlook.com.
   • Open Settings → Options/Settings → General → Region and time zone (or Regional depending on version).
   • Under Current time zone, select the correct Eastern time zone (for example, (UTC−05:00) Eastern Time (US & Canada)).
   • Save the changes and test by sending/forwarding a message again.
3. If using Outlook on the web in an organization (Exchange / Microsoft 365)
   • The mailbox regional configuration may be wrong on the server.
   • An admin can bulk-correct mailbox time zones in Exchange Online PowerShell, for example:

          $users = Get-Mailbox -ResultSize unlimited -Filter{(RecipientTypeDetails -eq "UserMailbox")}
          $users | %{Set-MailboxRegionalConfiguration $_.Identity -TimeZone "Eastern Standard Time"}
     

   • Replace the time zone string with the appropriate one if not in Eastern.
4. If only Outlook on the web shows wrong times but Outlook desktop is correct
   • This typically means the web regional settings are wrong while the OS/desktop are correct. Re-check step 2.

Once the OS time zone, Outlook desktop, Outlook on the web, and mailbox regional settings all match Eastern Time (UTC−05:00 with DST where applicable), new messages and forwarded headers will show the correct GMT offset.

References:

• How time zone normalization works in Microsoft Outlook
• The "Sent" time stamp on email messages is incorrect in Outlook on the web
• Manage time zone settings in Outlook
• Time zone settings are incorrect or missing for multiple mailboxes in Microsoft 365