How many hours is the time in the 6th time zone different from the time in the 9th time zone?

The Earth makes a revolution on its axis in 24 hours. Therefore, there are 24 time zones on Earth. The countdown is from the Greenwich (zero) meridian to the east. The time between adjacent zones differs by 1 hour. Time zones are numbered with Roman numerals.
IX – VI = 3 hours
Thus, there will be a three hour difference between these belts.
Belt IX is located to the east, which means that the time there will be 3 hours more than in VI.
For example, in the VI zone there are 12 hours, so in the IX zone there will be 15 hours.