Note: there is a known issue with Outlook not showing correct time for meetings and appointments with upcoming Daylight Saving Time changes. When appointment is open, it should display correct time. 

In order for the time of an appointment or meeting invitation to be reflected properly, settings in Windows and in Outlook must be correct and they must match. There is no reason to suspect that our servers have the wrong time settings since meetings and appointments time is always local to your mail client.

In Windows/Outlook:

    1. Open Windows Control Panel. Change "View by" in the top right corner to Small icons. Click on Date and Time to open it. 
      Instructions for Date and Time in Control Panel
    2. In the Time Zone section, make sure that the time zone and Daylight Savings Time settings are correct for your region. Instructions for Time Zone
    3. In Outlook 2010/2013/2016 go to File > Options > Calendar. Click the Time Zone button. Verify that the time zone settings are correct and that they are the same as the settings in the Windows Date and Time control panel. Instructions for Outlook calendar settings

In Outlook Web App:

Outlook Web App 2010:

Navigate to the top right corner of your browser window. Click on Options > See All Options... > Settings > Regional. Verify the settings for Current time zone.Instructions for OWA 2010

Outlook Web App 2013:

Navigate to the top right corner of your browser window. Click on the cogwheel. In the dropdown menu, click on Options. In the new window, navigate to Settings > Regional. Verify the settings for Current time zone.Instructions for OWA 2013

Outlook Web App 2016:

Navigate to the top right corner of your browser window. Click on the cogwheel. In the dropdown menu, click on Options. In the new window, navigate to General > Region and time zoneVerify the settings for Current time zone.Instructions for OWA 2016

In MacOS/Outlook 2011/2016 for Mac:

Click on the system time. Instructions for system time on MacOpen Date and Time > Time Zone. Instructions for Date & Time Mac Adjust the time if necessary (this requires administrative access). In Outlook, open Preferences > Calendar > Time Zones. Make sure the Default time zone for new events is matching your local time zone. Instructions for Outlook for Mac calendar settings

Read the Microsoft Knowledge Base article on How time zone normalization works in Microsoft Outlook​ for more information.