Primary Residence Tax Referral Duration

I am looking for some tax advice on the sale of a residential property, non investor owned. 

A client of mine is looking to sell his home, and move in with his girlfriend. They plan on buying a place in the near future, but are not ready yet. I understand that for investors there is a short 45 day period with which to "identify properties" under IRC Code 1031. 

What is the time period that regular people have when they sell their primary residence? I have heard multiple things. 

Thank you for the replies.