Certain time zones showing up incorrectly in Outlook calendar

European time zones such as Paris and Athens are working as designed in Outlook. Outlook stores all calendar items in Coordinated Universal Time (UTC) and then applies the daylight saving time (DST) rules for each time zone when displaying them.

In the time zone picker, Outlook shows the base offset (standard time) for each region, not the seasonal DST offset. For example:

• Paris is shown as UTC+1 because its standard time is Central European Time (CET, UTC+1). During DST it observes Central European Summer Time (CEST, UTC+2), but the label in the list remains based on CET.
• Athens is shown as UTC+2 because its standard time is Eastern European Time (EET, UTC+2). During DST it observes UTC+3, but again the picker label reflects the standard offset.

When a time zone is selected, Outlook automatically adjusts meeting times according to the correct DST rules for that zone. The underlying calendar entries are stored in UTC and converted to local time on display, as described in the “More about time zones in Outlook” section.

There is no additional setting required to “update” these time zones; they already include DST behavior. Use the appropriate city/time zone name (for example, Paris or Athens) and Outlook will handle the seasonal offset change even though the picker label shows the standard UTC offset.

If multiple time zones are displayed in the calendar time bar, be aware that on the first and last day of DST in either zone, the visual difference between time bars can appear off by an hour in some calendar views, but this corrects itself in subsequent views and does not change the actual stored meeting times.

References:

• Manage time zone settings in Outlook
• Multiple time zones show an incorrect time difference when DST starts and ends