Adjusting Time Zone in Doodle Poll – How to Change Time Zone Settings

They will shift to match the time zone when you created the event. For example an event at 15:00 in pacific time will remain at 15:00 in pacific time, but in your new time zone will be shown at 18:00 in eastern time zone.

Events can only display on your calendar in one time zone at a time. I'm not certain, but it sounds like you created the event for 13:08 in UTC+4, which Google Calendar was (correctly) showing to you as 12:08 in UTC+3 (your main time zone).

If you want to see events in another time zone (such as once you arrive in the other country), you would need to go to your Calendar Settings (in the gear menu) and change "Your current time zone". Or, instead of changing your current timezone, in the same place in settings you can add additional time zones.