回复：请问那位先生或女士知道大学F1申请大体需要多长时间吗？谢谢

If you mean I-20, it can be issued shortly (next day to a few weeks) after admission decision is made.
If you mean F1 visa stamp, once you have I-20, you can make visa appointment up to 120 days before school begin date.
If you mean change of status from current valid non-immigrant status to F1 status, see the I-539 processing time of your service center.