I've got a big csv with head movement data that I need to combine with an audio recording. The timecode in the csv doesn't start at 0, so I need to subtract the starting time from all entries.
The starting timecode looks like: 00:36:16:15.295
It's a bit confusing, I'm not certain what each number signifies. They all go to 59, except the part after the dot, which goes to 999.
How do I make the column start at a timecode of 00:00:00:00.000?
This is not a satisfying answer, but it is a solution to the problem at hand:
Using Data > Text to Columns... I split the timecode 00:36:16:15.295 into four separate columns: 00 | 36 | 15 | 15.295.
I then deleted the last column and created a new column with the following formula: =TIME(A3,SUM(B3,-36),SUM(C3,-16)). Using Format > Cells... I turned the resulting values into a time.