The iPad Air 3 currently doesn't have a set release date yet, and we probably won't officially find out until we hear it straight from Apple when the company sends out invitations to the press. However, there are a couple of interesting reports that have come up recently regarding the release of a new iPad.
According to a past report from 9to5Mac, the new 9.7-inch iPad is said to be revealed on March 15 where Apple is expected to hold an event. During this event, the company will also reveal new Apple Watch updates (like new watch bands), as well as the iPhone 5se (a.k.a. the iPhone 6c).
However, newer reports from Recode and BuzzFeed say that Apple will hold its March event on March 21. All three of these sources are known to be reputable, so we're not quite sure what to believe, but a March event seems to be agreed upon.
If this is true, then it would be the first time in several years that Apple has released an iPad earlier in the year. The first three generations of iPads were all announced during the first-half of the year, until Apple moved the announcements to the fall. So this could be a sign that Apple is going back to the past with its iPad release cycle.