The world is divided into different time zones (please see Wikipedia for further details). Some/most time zones use daylight savings time but not all. Modern calendar systems like Google Calendar save events with a globally unique time, they use UTC (GMT+0 without daylight savings time) times for all events. Based on this UTC time and the currently used time zone of the user, they calculate the correct time for the user’s time zone.
The following example shows how an event entered for 10am in New York for different months is saved in UTC time and how it is displayed in other time zones like Berlin or Reykjavik:
So when you travel into another time zone and change your phone’s time zone, the your events will be displayed with this new time zone so the appointment times will change. If you don’t want this, you can simply use a fixed time zone for your calendar: Just set “Settings”, “Display and Use”, “General”, “Time zone” to your home time zone. Then your events will be displayed with the same times regardless which time zone your phone uses.
Using a wrong time zone and then changing itIf you used a wrong time zone, i.e. a time zone without DST and later change it to a time zone with DST, this will show your events with a different time afterward. Please see this example:
Changing time zone settingsIn CalenGoo you can see your current time zone configuration under “Settings”, “Time zones”:
There are different time zone settings you can configure:
If your phone doesn’t have this option you can install an app to change your phone’s time zone, e.g. “TimeZone Changer”.
If you set your phone to a fixed time zone, you can additionally specify which time the red line that indicates the current time in the day view should display (and this way also which time should be used for the reminders):
It can either take your current time zone into account and display the time of your HOME time zone (the one your Google calendar uses) (“Red line displays local time” OFF) or it can simply display the current time of your phone (“Red line displays local time” ON):
The time zones of your calendarsEach calendar in Google Calendar has its own time zone. You can configure them in Google Calendar by clicking the names of your calendars in the calendars tab:
So if your phone’s time zone is correct and you cannot change Facebook’s time zone, this problem occurs. Many people seem to have this problem (even without using CalenGoo):
So the problem seems to be that your Facebook account uses a wrong time zone.
A possible workaround seems to be to sync the Facebook account via Google Calendar instead of directly with your phone: Sync Facebook