Timing the purchase of a 1031 exchange

I'm selling a SFH and hope to 1031 into a commercial prop. I can get the tenant out of the SFH by end of May. So sale will hopefully be by end of June.

Given that timing, when should we start making offers on commercial properties? Right away? Or closer to June? 

As you can probably tell, this will be my first 1031 exchange, so any help will be greatly appreciated.