one: Greenwich Mean Time
24
mongolia have 4 different time zones
The UK and Mali share the same time zone !
Zimbabwe has 4 different time zones because it's a small country.
Austria uses Central European Time.
There are 24 different time zones around the world.
none
There is a 6 hour time difference. It is actually 7 time zones different, as some time zones are not 1 hour.
At any given time, the clocks around the world are set to at least 38 different times, and these time zones have about 165 different names, including about 130 different names just for Standard Time designations.
Only 1
Russia has 9 different time zones, 8 contiguous and another one in Kaliningrad.
Malawi has only one time zone.