About a year ago, we announced Exchange Server Security Changes for Hybrid Deployments. This change impacted Exchange hybrid customers who host some of their mailboxes on-premises and their on-premis...
Updated Aug 31, 2026
Version 6.0
Blog Post
Shortly after implementing the new Graph API, our on‑premises users started complaining that cloud mailbox calendars were displayed two hours earlier in Outlook (classic). Appointments were shifted by –2 hours compared to our local time zone. Appointments scheduled during the winter period were shifted by –1 hour.
This led me to conclude that Outlook (classic) was no longer honoring daylight saving time rules, and that the appointments were being interpreted as UTC. OWA did not have this issue; appointments were displayed correctly there.
It took me some time to identify the cause, but after deleting the override EnableRouteThroughMSGraphFeature in our Exchange environment, Outlook (classic) started displaying appointments correctly again.
The regional settings on both the on‑premises and cloud mailboxes are configured for the same time zone. The regional settings on our Exchange servers are also configured identically.
Is this a known issue, or do I need to configure a specific regional or time zone setting elsewhere?
Hi, same issue here. Did you have any luck fixing the issue? Disabling EnableRouteThroughMSGraphFeature corrected everything but going to need this enabled in the near future.