Know the Greenwich Mean Time (GMT) by your wristwatch

Say it is 7.10 p.m. (IST) by your watch. IST is India Standard Time, which is 5 hrs 30 min ahead of GMT. So GMT would be 1.40 p.m. You turn your watch by 180° so that the minute hand is at the position of ‘8’ and the hour hand between ‘1’ and ‘2’. You may have to conceive the position of the hour hand very slightly ahead of where it actually stands. So there you are! The time is 1.40. It holds for any time. Make sure that your wristwatch has the hands, it should not be digital.