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…