Your closing date is normally stipulated in the purchase agreement that both the buyer and seller agree to. Closings involving financing could take between 30 and 60 days. On the other cash transactions could take place in one to two weeks with a home inspection included.
In the event you are speaking of a "short sale" plan on a much longer term prior to closing. In some cases 4-6 months.
If you are in the process of shopping for a home now, a local real estate professional will be able to guide you through the process.