Explanation:

There are two factors that are responsible for this phenomenon - longitude and time zone.

Longitude:

Longitude is the angular distance of a place east or west of the prime meridian. The prime meridian passes through Greenwich, London and is assigned a longitude of 0 degrees. As one moves eastwards from the prime meridian, the longitude increases and as one moves westwards from the prime meridian, the longitude decreases.

Time Zone:

A time zone is a region of the globe that observes a uniform standard time for legal, commercial, and social purposes. Time zones are usually defined as the offset from Coordinated Universal Time (UTC). As one moves eastwards from the UTC, the time zones increase and as one moves westwards from the UTC, the time zones decrease.

Reason:

Arunachal Pradesh is further east than Gujarat. Therefore, Arunachal Pradesh is ahead of Gujarat in terms of longitude. This means that the sun rises earlier in Arunachal Pradesh than in Gujarat. However, both Arunachal Pradesh and Gujarat fall under the same time zone in India. This means that they follow the same standard time, which is determined based on the UTC offset.

Conclusion:

Therefore, even though the sun rises two hours earlier in Arunachal Pradesh as compared to Gujarat, the watches show the same time in both regions because they follow the same standard time zone.

As the longitudinal gap between Arunachal Pradesh and Gujarat is about 30 degrees, the time lag between these two states is two hours. Since Arunachal Pradesh is situated in the east, the sun rises earlier here compared to Gujarat in the west. But the watch shows the same time because of the Standard Meridian of India.