I had a lovely time wandering around Jaipur with Shalobh, a most articulate guide, to see the largest sun dail in the world 'Samrat Yantra' made of marble and stone, built in 1727. It's gnoman stands 24 meters high, which measures apparent solar time.
It even measures time at night, provided one has some knowledge about the movement of the stars, specifically that a star makes a complete revolution of the earth in 23 hrs, 56 minutes and 4.09 seconds which is the length of the sidereal day.
Afterwards, we walked through the flower market to the City Palace. There we met the most charming man, whom showed us how he wraps his turban. Shalobh said, 'It's not as easy as it looks'.
A man must know something about the time it takes for him to make a complete revolution around his head. It took him exactly 40 seconds in sidereal time.