Cannot import entries for month September

[ltog]

I had an issue when trying to export from Android 10 (/e/OS 1.5) and import into Android 13 (/e/OS 2.0-t) (both STARWeight version 15): Entries from month September were not being imported (i.e. just skipped), while all other months worked properly. (I did not test July.)

The entries for September were visible in the export like this:

31 Aug 2023,118.5
01 Sep 2023,118.5

However, to make the import work I had to change them to:

31 Aug 2023,118.5
01 Sept 2023,118.5

In other words: I had to change Sep to Sept. The other months worked fine, so I did not have to adjust anything for these. Quite strange...