Lol. I am very familiar with how it is supposed to work. It is like you say, a rolling system of refills over a period of time. That time was 23 hours. @Ryvirath raised the Like limit from 50 per to 100 per period.
So to do what I do, I would use all 100 Likes in one burst, and then wait 23 hours for the first Like to refill. If I was able to use the Likes all within 1 second of each other (that is to say that all Likes would be used in under 100 seconds) the system would not recognize the measure of time being less than 1 second.
To further illustrate: If I used all of my Likes starting at 5 pm (and within 100 seconds) I could then repeat the process starting at 4 pm the next day (all within 100 seconds or less!).
There is something fishy happening, or the rules have been changed. That pattern was not working, regardless. The strange part is when I was getting the notice of hitting the limit. The number would be 240 hours, and then the very next notice would say 15 hours, or 237 hours, or 8 seconds, or whatever number. At least that is what was happening earlier.
I will test again soon.
Or 219 hours, which I literally just got.