Build, test, and debug regular expressions
Matches timestamp lines in SRT subtitle files, such as '00:02:17,440 --> 00:02:20,375'. Each timestamp is built from three groups of two or more digits separated by colons or commas (hours:minutes:seconds,) followed by the millisecond digits, with start and end times joined by an arrow. Useful for parsing, validating, or extracting subtitle timing entries from .srt files.