If you want the fare to be cheapest, best way to travel would be during the non peak hours. Peak hours include morning and evening office times and during rains. Hope this helps.
How far in advance should I book an Uber?
Request a ride up to 90 days in advance at any time of the day. Make sure to schedule a Reserve trip more than 90 minutes prior to your departure to access the full benefits of the trip. To schedule a Reserve trip, go to the Uber app on your mobile device and: Select Reserve on the home page in the app.