It varies with the server and how much work was done. If you explain it to the person it might go better. At some places the server gives a cut to other staff that help with the table. At cafes with a tip jar it is divided up at the end of the shift. The only certain rule is don’t tip with those fake half bills with a religious flyer on the other side.
An hour to six days is bad. There must be some kind of data ingestion and pipeline involved. Reading a database and generating a formatted xlsx file can be a few seconds to minutes.
An OpenXML library could modify and write to a new file without Excel. Microsoft’s version is usually for C#, there are similar libraries in other programming languages if your computer is locked down. If Excel gives a corrupted error when opening, the XML data can be viewed by renaming the xlsx extension to zip.
Merging Cells: https://learn.microsoft.com/en-us/dotnet/api/documentformat.openxml.spreadsheet.mergecells?view=openxml-3.0.1
Cell style and background color: https://stackoverflow.com/questions/44839512/how-to-work-with-style-index-in-open-xml
I’m more of a van Gogh, misunderstood until after his time.