Time is of the essence in real estate deals. Both parties should try to move forward as fast as possible by the dates agreed upon. If you have a verbally accepted offer and you are waiting for your written offer to be signed by the seller, they should try to get that back to you as soon as possible. You don't really have an accepted offer until it is in writing by both parties. If they are taking too long to get it back to you after verbally accepting it then something maybe wrong and you should have your agent find out what is going on. However, if you are dealing with a bank owned property it may take a longer amount of time to get the signed offer/contract back from the bank (3 to 4 business day response time is not unusual for banks).