Application deadlines for grad schools are commonly from mid-November to mid-December. After the holiday break, once all the materials are in, filed, etc., the Admissions Committee will begin reviewing all of the files. Expect acceptance to go out, depending on the school, around March, after committee members have reviewed every file, and met to discuss them.
Remember it's a huge work load, and each department can have hundreds of applications. Professors on admissions committees have a huge workload, on top of their usual teaching & research.