There are four FBS college football games on Aug. 25, two Saturdays before Labor Day. All of them can happen then because of an NCAA rule about the Hawaii Rainbow Warriors.

Generally, teams can’t start before the Thursday before Labor Day. But the rules are different for the Rainbow Warriors and teams that visit them.

Here’s the exception in the NCAA’s scheduling rules.

An institution that is scheduled to play a regular-season game in Hawaii may play its first permissible contest with outside competition on the Saturday prior to the Thursday preceding Labor Day. If the institution’s first opponent of the season is not a member institution located in Hawaii, the institution’s first opponent of the season may also play its first contest (game or scrimmage) with outside competition on the Saturday prior to the Thursday preceding Labor Day.

Along with starting earlier, if an FBS team visits Hawaii, it can play 13 regular-season games instead of 12 and still finish by the NCAA-mandated second weekend of December. (FCS teams can play 12 regular-season games instead of the usual 11). The Rainbow Warriors also get 13 games if they want them, though they have just 12 on the schedule in 2018.

(There’s a separate schedule exemption that allows FCS teams — one per conference per year — to start early if they’ve got a national television broadcast to show the game. That’s why you get to watch Jacksonville State and North Carolina A&T on ESPN on Saturday, too.)

The 13-game exemption for Hawaii and its visiting opponents has been around for years, but a tweak in 2016 gave it more teeth.

Previously, these teams could play 13 games, but they’d have to do it in 13 weeks. There are only that many weeks between the Saturday before Labor Day and the Saturday after Thanksgiving, when conferences finish their regular seasons. The only regular-season game after that weekend is Army-Navy.

Letting Hawaii and all of its visitors play a 13th game was nice in theory, but it wasn’t as attractive when it forced teams to skip their bye weeks if they wanted to do it.

Now FBS teams that start early and play a game in Hawaii can either play 13 games in 14 weeks or just play 12, with a nice extra bye week. The Week 0 opponents of those teams also get the benefit of an extra bye.

You can see how the Hawaii exemption shapes this first mini-week.

Consider the four Aug. 25 games with FBS teams:

Hawaii at Colorado State : The Rainbow Warriors get to start early, and so do the Rams, because they’re playing against a team (UH itself) that has a game in Hawaii.

: The Rainbow Warriors get to start early, and so do the Rams, because they’re playing against a team (UH itself) that has a game in Hawaii. Wyoming at New Mexico State : Wyoming visits Hawaii in Week 6, so the Cowboys and NMSU can both start early in Las Cruces.

: Wyoming visits Hawaii in Week 6, so the Cowboys and NMSU can both start early in Las Cruces. Prairie View A&M vs. Rice : Rice visits Hawaii in Week 2.

: Rice visits Hawaii in Week 2. Duquesne vs. UMass. Duquesne visits Hawaii in Week 4.

Duquesne’s playing the FCS-standard 11 games with two byes. Wyoming’s playing the FBS-standard 12 with two byes. Rice is playing 13 with one bye.

Hawaii is the whole reason there are games this week.

College football fans owe the Rainbow Warriors a hearty mahalo.