Standard Time :
1. Local time of a place is based on the longitude of that place. It means places situated on different meridians will have different local times.
2. It creates much confusion and problem for people to function in a country.
3. It is 1 hour and 45 minutes time difference in the local time between Dwarka (Gujarat) and Dibrugarh (in Assam).
4. To solve these problems every country fixes its central meridian, which is considered the standard meridian of that country.
5. The local time of this meridian is considered standard for the whole country. It is called standard time.
6. In India, the longitude of 82 Vi° E (82° 30° E) is treated as the standard meridian.
7. The local time of this meridian is followed all over the country.
8. This is known as Indian Standard Time (IST).
9. Through an international agreement, the local time of all places is linked to the Greenwich Mean Time (GMT). Different places have different times.