Euphoria put the schedule for next day around 2 am, so send a text as soon as you can. By noon 3/4 of the roster is already fully book. They also have lots of daytime girls recently too so obviously you have to book fast
Xo have a weekly schedule so pre-book as fast as possible for you, they have same day add on as well so look at the schedule
Unicorn, text them and ask about the day/time that would fit the most for you, due to there specialty services, pre-booking is better
XXXtase, Vogue and MTLGFE, and a various number of other agencies either post the day before really late or same day, so when there schedule is up is the best time to book.
Indies usually like pre-booking at least a day in advance, but 2-3 is even better.
Hope it help you