we enter it at the time we get it, so like this it shows up in the deposit report at the date the check is available .
now with reports, most of the time it works by date you select, like from 9/1/14 to 8/16/15 you wont get any head checks past today .
and on balance reports where you don't want to chase someone that has a post dated check there are reports you can get that show future checks .
also be advised there a few ways how you can enter postdated checks and for one way there is a sub tab in payments called detail. (you should discuss with JL support witch way to enter it each way has pros and cons depends on your set up.)