This holiday weekend, you might want to consider checking in extra early at the airport. There’s evidence some airlines, in an effort to boost their on-time ratings, are instructing their flight crews to push back a minute or two early — and leaving some passengers stranded at the gate.

So-called “leave-early” policies have been around for as long as the Transportation Department has published on-time statistics, as I pointed out about a decade ago.

What’s different now? I’ll have the answer in a moment. But first, let’s hear from Aletheia Lawry, who was on the wrong side of an early departure on a recent Delta Air Lines flight from Houston to Hartford.

We were late pulling into Atlanta — we were forced to circle the airport for about 15 minutes and then were on the tarmac another 10 minutes or so while they tried to find an open gate.

We exited the plane and ran to make our connection to Hartford. We arrived at the Hartford gate about eight minutes before scheduled departure. The plane had already left. We banged on the Jetway door, to no avail.

Indeed, Delta tells passengers that they must be at the gate 15 minutes before departure or they risk missing their flight. Some cities have longer lead times (45 minutes for St. Croix and St. Thomas) while others are shorter (shuttle flights in Boston, New York and Washington have just a five-minute requirement.)

Not that the rules are doing Delta any good. Roughly 84 percent of its flights were considered “on-time” in September, according to the Department of Transportation (PDF). That’s about average.

Lawry is amused by that.

It amazes me that even with dispatching flights early, Delta can have such a dismal on-time record.

I’m not asking for a return to the times when they would hold a plane for connecting passengers, but to leave us sitting in the Atlanta airport because they left prior to departure time seems unconscionable. Can they actually do this to passengers?

Well, yes.

In fact, with more Web sites displaying on-time statistics by flight, and with executive bonuses being tied to on-time records (US Airways, for example) the pressure is on to push back as early as possible.

Meaning that when it comes to air travel, early is the new late.