Hello Jivan28,
There are several series with that title, am not sure if you are referring to the BBC version I did some work on, or for the new series (2019) of the same name.
Would also like to thank newkinds for his reply, I've used this tool many times and it does have its' usefulness in tweaking of subtitles. However, it is not the subtitle panacea for all instances.
I recall doing several resyncs for you in the past where tools like subsync and many of the point sync sub utilities are not viable solutions. In both of those cases, a reasonable amount of work/time went in to tweaking subtitles, due to various differences in the video source that you were requesting sync to.
viewtopic.php?f=1&t=17228&p=44253&hilit ... les#p44253
viewtopic.php?f=1&t=17268&p=44417&hilit ... irl#p44417
To properly sync these subtitles, this required not only the text based sub files, but also the "actual video source" in which to sync to. These can sometimes be difficult to acquire.
SmallBrother wrote a very nice response prior in addressing synchronization and the complexities involved. He is a much better wordsmith than I, here he describes the process and many of the issues involved, from a prior request you submitted.
viewtopic.php?f=1&t=16514&p=40085&hilit ... FPS#p40085
Hope this helps...........