When the sun rises in Arunachal Pradesh, it is still night in Gujarat because:-
1) The earth rotates from west to east and so, the sun rises earlier in Arunachal Pradesh than in Gujarat.
2) The sun rises from the east and moves toward the west. Arunachal Pradesh is to the east of Gujarat.
3) There is 2 hour difference between the meridians of Arunachal and Gujarat. This causes a time lag of 2 hours. So, it is still night in Gujarat when day in Arunachal.