HM:AWL the difference in in-game time between regions

If you've ever played Harvest Moon: A Wonderful Life, you may have assumed that the in-game time was completely 1:1 with real time, but this may not be the case for everyone. In actuality the in-game time in european copies of the game (PAL) varies slightly from the one in North American and Japanese copies (NTSC)

It's pretty common knowledge that most NTSC copies of games, especially older games, have a higher fps, causing it to be faster in speedruns, but that doesn't really explain why the in-game timer of AWL varies from NTSC to PAL. Without thinking too much about, it seems like the time in AWL is completely 1:1, every 1 second in real time, is a minute in game time, and chances are if you timed this, you're probably right.
This is because for NTSC copies of the game, this is the case. But if you've timed the seconds on a PAL copy of the game, you may have noticed that the in-game time and real time start to fall slowly out of sync.
The only possible explanation for this is that in-game time is based off of something that changes between the different regional versions.
The frame rate.

In NTSC games there are 30 frames in a second, whereas in PAL games there are 25. Now obviously if the in-game time was programmed to go up by one each second, it would always be 1:1. So why is that only NTSC is 1:1?
My theory is that the program counts in frames, and was programmed to increase the in-game time by 1 after 30 frames, the standard for NTSC games. This means that when the game was changed to 25 fps for PAL, the in-game time still worked in gaps of 30.
In the NTSC copy of the game, when 30 frames pass, so does a second in real time, as well as the an in-game minute. In the PAL copy of the game, when 25 frames pass, 1 second in real time passes, but not in-game time, because the program is still counting until 30 to increase the in-game time.
This means when a minute in the PAL copy of the game passes, 1.2 real time seconds have passed.
On the surface this may look like nothing, and chances are you won't notice, but over time those .2s add up and become seconds. Those seconds then become minutes, and so on.

If you were to wait a real life minute on an NTSC copy of the game, then you would have waited exactly 1 in-game hour.
If you waited 1 real life minute on a PAL copy, you would have waited 50 in-game minutes.
This means if you've played the game for 6 minutes, on an NTSC copy you would have played for 6 in-game hours, whereas on a PAL copy you would have played for only 5 in-game hours.

So where does this all come into speedrunning the game?
When speedrunning the main categories (marriage) there are various events determined by time.
For all 3 of the girls, certain cutscenes are only able to be activated within certain time frames.
Such as:
The majority of Celia's cutscenes
Both of Muffy's cutscenes
Nami's cutscene
and obtaining the horse in a Nami run.

Because in-game time passes slower on PAL, the time windows for cutscene are open on different days.
This causes various things to change in a speedrun when running on different version.
On NTSC, Muffy's 1st cutscene is most likely going to happen on Spring 2 instead of Sprign 3 on PAL.
Celia's 4th cutscene is more likely to activate later in the year on NTSC than PAL.
It may be harder to only have to do one cycle in a Muffy run on NTSC due to time being "faster".
Because of how close you are to passing the time frame for getting a horse in Nami runs on PAL, you may not be able to get a horse straight away on NTSC.

Most of these differences aren't confirmed, but going by how the in-game time differs, they could very well be the case.
I'm not saying anything for definite, but this could lead to the possibility that PAL is actually faster for Wonderful Life marriage runs.