I get an error:

date +%s -r ./suc.zip
date: illegal time format
usage: date [-jnRu] [-d dst] [-r seconds] [-t west] [-v[+|-]val[ymwdHMS]] ... 
            [-f fmt date | [[[mm]dd]HH]MM[[cc]yy][.ss]] [+format]

Strange, but it does not seem to work.
I try with hardcoded times.

Geir

28. jan. 2018 kl. 21:00 skrev Michael Balzer <dexter@expeedo.de>:

date +%s -r somefile