Power Query imports date as number and is off by 4 years and one day

[Mahar92]

Hello there.

I am currently doing a job for a client and I encountered a problem that leaves me completely dumfounded:
I am importing data via Power Query from an external Excel workbook. The first column has dates (see first picture).
When I import that file into Power Query, it immediately turns the date into a date value (never experienced that behavior before).
That would not bother me so much if the date would not be off by 4 years and one day.

This happens on both mine and the client's machine. We use the German date format.

Help!

 

[KRice]

The 0 date baseline date differs by 4 years and 1 day between Windows and MacOS.

Date systems in Excel - Microsoft Support

Learn about the 1900 and 1904 date systems and how to change the default if necessary.

support.microsoft.com