I know that many people here don’t like this idea, but in my sons’ school, if a boy came late too often, they confiscated his shoes. [i’ve mentioned the idea elsewhere in the CR.] It definitely makes them desperate to get to school on time.
In my kids school, if the kids come late, the first time they cut off their hands, and the second time they kill them. It definitely makes them desperate to come to school on time.
After a while, all the late coming kids are killed, and then only the kids who come on time are left, and the problem is solved!!
(This post has two points. Only a select few will figure both out. I originally explained here, but then felt guilty for doing so, so I edited it out.)