Hey Nvxwax,
You need to provide the full detail about your setup when asking any kind of questions. With only the symptom, we can not do much. Here, an important piece of info that is missing is your FreeNAS version.
The snapshot tagged as 2020-02-29_00:00 was taken at the proper time, but is not named after the retention period.
On the other end, the one taken later at 04:15 in the morning is not on this schedule but is named with the retention period.
That looks like 2 snapshots taken by 2 different tasks. So for that, also provide the list of all your snapshot task, not only the description for one of them.