The spinning of the earth around itself is known as rotation/axial motion.The movement of sun around the sun is called revolution/orbital motion.
Daytime changes with the seasons.The time of sunrise and sunset is not the same at all places on the meridian.It changes according to lattitude.However midday occurs at the same time at all places on the meridian.Midday occurs at different times on different meridians.
When the time at a place is given with reference to its midday,it is called the local time.There is a difference of 4 minutes in the local time of places on two meridians that are one degree apart.Countries which have a great expanse from east to west,generally adopts the local time of the central meridian as the time for the entire country.This time is called the Standard time of that country.There is a difference of 29 degrees of longitude between the easternmost place in Arunachal Padesh and westernmost place in Gujrat.It means there is difference of 1 hour 56 minutes.Indian Standard Time(IST) is based on the meridian 82 30` east.This meridian passes close to Allahabad in Uttar Pradesh
The meridian which passes Greenwich is considered as the prime meridian.Hence the difference in the standard time of different countries is told according to Greenwich time.Indian Standard Time is 5 hrs 30 min ahead of Greenwich.
Daytime changes with the seasons.The time of sunrise and sunset is not the same at all places on the meridian.It changes according to lattitude.However midday occurs at the same time at all places on the meridian.Midday occurs at different times on different meridians.
When the time at a place is given with reference to its midday,it is called the local time.There is a difference of 4 minutes in the local time of places on two meridians that are one degree apart.Countries which have a great expanse from east to west,generally adopts the local time of the central meridian as the time for the entire country.This time is called the Standard time of that country.There is a difference of 29 degrees of longitude between the easternmost place in Arunachal Padesh and westernmost place in Gujrat.It means there is difference of 1 hour 56 minutes.Indian Standard Time(IST) is based on the meridian 82 30` east.This meridian passes close to Allahabad in Uttar Pradesh
The meridian which passes Greenwich is considered as the prime meridian.Hence the difference in the standard time of different countries is told according to Greenwich time.Indian Standard Time is 5 hrs 30 min ahead of Greenwich.
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