While we didn't set out to solve those problems in Neptyne, using actual data types in a spreadsheet does solve this sort of problems. Of course we have to be a little compatible, so our dates do come with the 1900 is a leap year bug that pre-dates excel. But they also have a .to_datetime() if you want to be more sophisticated. We have great plots out of the box, but if we want to go deeper, you can use whatever plotly or pydeck construct gets you exactly what you want.