The world is divided in to 24 time zones of one hour each.The earth rotates 360 ° in about 24 hours,which means 15° an hour or 1 ° in 4minutes.
- Russia has eleven time zones spans over 170 ° of longitudinal extent.
- USA has 5 time zones.
India spans over 30° of longitude and has two time zones.But it has adopted one standered time for the sake of convenience.In India,the longitude of 881/2°E is treated as the standard meridian.The local time at this meridian is taken as the standard time for the whole country.It is known as the Indian Standard Time.India located east of Greenwhich at 82°30'E is 5hr 30min ahead of GMT.
| 1°=4min |
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