Subtitle synchronization issue (24 --gt;25fps) only, contain, created, getting

andy

I have a movie that is 24 fps. The subtitles I downloaded where in .srt format. As you probably know, .srt files created with Subrip contain only time information for each subtitle. They don't say in which frame a subtitle is played, but in which second. When I started watching the movie, I noticed that the subtitles where progressively getting out of synch. The subtitles where played before the actor had spoken.

I fixed the subtitles. I used a subtitles convertor program and changed the fps to 25 fps. BUT: If had chosen to save the re-calculated file in .srt format, the timing wouldn't change. I accidently saved in MicroDVD format and it worked! Subrip format uses time to synchronize the subtitles. MicroDVD uses frames! So , any change in FPS, doesn't affect the Subrip format as the time a subtitle is played is always the same.
On the other hand, the frame a subtitle is played is different and depends on the framerate. But I am still confused:
How could Subrip (.srt file) mess up the timing , as it uses time oriented synchronization?? My movie could be 5 fps or 205 fps, but the time (in seconds) that each subtitle is played is always the same... Anyone has any ideas?

Beginner post. 25 fps runs faster than 24 fps, so times are shorter (movie runs 4% shorter time).

You can of course change srt subs also to different framerate. There is lot of programs for that....