Jai Singh believed that larger instruments would produce more accurate results. With that idea in mind, he created the Samrat Yantra, a sundial that is 23 meters (75 feet) high, and which keeps time to within a second a day. As the sun makes its way through the sky, it casts a on the semi-circular curve of the Samrat Yantra, and from this local time can be established. It is still used to confirm the date of religious holidays and to forecast crop prospects for the coming year.