Understanding Time Zones and Calculations

What is local time primarily based on?

• The position of the Moon

• The position of the Sun at a particular place

• The time in London

• The International Date Line

If it is 12:00 noon at the Prime Meridian (0° longitude), what is the local time at 30° East longitude? (Assume 4 minutes per degree)

• 2:00 PM

• 10:00 AM

• 2:00 AM

• 12:30 PM

Indian Standard Time (IST) is based on which longitude?

• 0° longitude

• 82.5° East longitude

• 45° West longitude

• 90° East longitude

How many hours ahead of Greenwich Mean Time (GMT) is Indian Standard Time (IST)?

• 3 hours

• 5 hours 30 minutes

• 4 hours 30 minutes

• 6 hours

What is the main purpose of the International Date Line (IDL)?

• To set the time for the whole world

• To mark the place where the date changes by one day

• To determine local time

• To calculate Indian Standard Time

If it is Monday just west of the International Date Line, what day is it just east of the line?

• Monday

• Tuesday

• Sunday

• Wednesday

Greenwich Mean Time (GMT) is the time at which longitude?

• 90° East

• 0°

• 180°

• 45° West

If the local time at 75° East is 3:00 PM, what is the local time at 90° East? (Assume 4 minutes per degree)

• 4:00 PM

• 2:00 PM

• 4:30 PM

• 3:30 PM

How many time zones are there in the world?

• 12

• 24

• 36

• 48

If it is 6:00 PM GMT, what is the time in IST?

• 11:30 PM

• 12:00 PM

• 6:00 AM

• 3:00 PM