Ed,
No it doesn't take a long time and they should have given you a schedule (how long to hold it between voids along with exercises for strengthening the pelvic floor muscle) when you got out of the hospital.
At first you should empty every two hours for a couple of weeks, then three hours, then four hours. This is just my recollection as I don't have my post op information anymore.
Here is a link to a guide:
Achieving Continence with a Neobladder
Maybe somebody who had a neobladder recently can post what their schedule was. Night time is a little longer than day time in terms of how long you go without emptying.
Usually, the neo is 40-80cc capacity when you come home and by holding it longer over time, it causes the neo to stretch.
Then the doc should have you empty at your appointment and then do a scan thing like a sonogram in the office to see how much residual is left. This is to be sure that you are emptying fully because you can overstretch if you wait too long between voids. The overstretching can cause problems if it gets too big.
Mike