wrong subtitle start time when trying to hardcode them into video using ffmpeg
FFmpeg normalizes timestamps to start from 0 after seeking. So workaround is to copy timestamps and then set output ss to exclude unwanted portion of input.

ffmpeg -ss 01:01:00.0 -copyts -i input.mp4 -vf subtitles=input.srt -ss 01:01:00.0 -t 00:02:00.0 output.mp4