What is a delayed exchange?
It can be hard to find a like-kind property immediately available for a 1031 exchange and that the owner wants to swap for your property. Therefore, there's such a thing as a delayed exchange. In a delayed exchange, an intermediary holds the cash after the property you wanted to exchange is sold outright and then uses it to buy another property that would otherwise qualify for a 1031 exchange.
You must choose your new property within 45 days of the sale. In fact, you can generally designate up to three properties as long as you close on at least one (in some cases, you can choose more). You also must close on the new property within 180 days of your initial sale. Since these exchanges don't happen concurrently, they're considered delayed.