This is one of the silliest questions that I see asked around. Let me answer this one final time: Each university has its own deadlines for applications for the two semesters. There is no one deadline. If you want to find deadlines for specific universities, please consider using a very well known invention called Google. Find the website of the university, go to the section for prospective students and you will find all the deadlines listed there, along with almost all information that you could ever require. In general, please consider doing a little bit of research yourself before asking others.

If you still need a very general idea of the deadlines, Fall semesters usually have an application deadline of mid December or early January, whereas Spring deadlines are usually in August or September.