One of the terms commonly addressed in a real estate offer is the length of the due diligence period.
The due diligence period allows the buyer to make all necessary inspections and investigations about the condition of the property and the neighboring area.
A seller does NOT have to agree to ANY amount of time, but most buyers would either walk away or offer a lower price.
ANY period of time can be negotiated between a buyer and a seller. Typical number range from 7-14 days for single-family residential properties and substantially longer for raw land, commercial, or multi-family parcels.
Keep in mind that a seller is keeping the property off of the market during this time and has an interest in "moving things along."
Buyers should be allowed a reasonable amount of time to determine if the property is suitable before laying out thens of thousands or hundreds of thousands of dollars.
Buyers should move expeditiously and methodically, and NOT put off critical inspections to the last minute. It is better to have sufficient time to address all of the buyer's concerns without the need for termination the contract.
So how long should a due diligence period last?
As long as is agreed to by all parties to the contract!