I'm trying to export string types to a calculateable custom number format using SheetJS. SheetJS provides types like Number and Date but none for custom formats. When I set the .t to n and .z to e.g. hh:mm:ss,000 Excel is resetting the format due to invalidity.
Values could be e.g. 1:52:03.401, 12:19.4, 1:03.21, 3.26 - basically HH:mm:ss.SSS
Those values are being calculated from a timestamp to a string. Any ideas on how to approach this issue?
