Hey,

NTA conducts JEE main paper in two shifts. The duration of both the shifts are same. First shift timings are from 9:30 am to 12:30 pm and second shift timings are from 2:30 pm to 5:30 pm. There are total eight shift which spans for 4 days divided by morning and noon shift. However, NAT haven't given any fixed pattern that morning shift will comprise of easy level of questions or noon shift will comprise of high level of questions. It just your luck which type of questions you get and how much practice and knowledge you have. However, JEE main paper comprises of moderate level of questions.

Good luck!!