1. You should have a recorded script
2. You should have some knowledge of the logic of your application, and identify which request inside the script send the scheduling date/time to server.
3. You can make the data/time dynamiclly changed. For example, you can use date/time API of LoadRunner to get replay time date, and save it to a parameter, then replace the corresponding values in the request part of script. You can also predefine some dat/time using LoadRunner's parameter file and retrieve them during replay.