Loss and gain of time

If any person travels from India to US, there is gain in time.
If travels from US to India there is loss of time. Why?

Answer1:

this is not physics issue... hope u have heard of timezones.. IST.. EST.. PST ..this is due to the difference in these timezones

Answer2:

Conventions for standardization of time (you see on wristwatch).

Answer3:

Yes,when we go from INDIA to US there is a gain of time and vice-versa. This is because earth rotates from west to east and US is in west from INDIA so if we go with plane,the relative velocity of plane will increase as plane goes from east to west and vice-versa.