Check what time zone you have set on your calendar:

1. Go to your outlook Calendar
2. Click on the gear wheel at the top right of your screen
3. Check the location and time zone under the Current time zone option at the bottom of the window
4. Select Auto Time Zone option
5. Confirm the change

Check that the calendar time zone is the same for others:

1. Open your calendar
2. Select the meeting or event in question
3. Click Invitees at the top of the screen
4. Look at the time and time zone displayed next to each attendee
5. If the time zone differs from the one you have set, ask the attendee to check their settings