How will you know the time if there were no clocks, no wristwatches, no mobiles, and no other piece of technology to assist you? Impossible isn’t? Well if you are in Delhi/Jaipur/Ujjain/Varanasi there is a way – thanks to Maharaja Jai Singh II of Jaipur who built a set of astronomical instrument structures known as Jantar Mantar. The 5th one built at Mathura no longer exists.
The instruments have got interesting shapes – some with stairs while some have huge dials. In addition to time, you can measure altitude and azimuth of celestial bodies, find the position of constellations, find out the longest and shortest day(s) of the year etc. Visit Jantar Mantar and bring out the astronomer in you.
Please note that the readings taken from these instruments are based on the position of the shadows cast by the sun. So if you want to measure time in the middle of night, I am sorry you will have to wait till sunrise.