https://bugs.openldap.org/show_bug.cgi?id=10582
--- Comment #5 from Peter Dyballa Peter_Dyballa@Web.DE --- Just checked with another Mac that has sw_vers
ProductName: Mac OS X ProductVersion: 10.13.6 BuildVersion: 17G14042
It also has:
-r seconds Print the date and time represented by seconds, where seconds is the number of seconds since the Epoch (00:00:00 UTC, January 1, 1970; see time(3)), and can be specified in decimal, octal, or hex.
-r filename Print the date and time of the last modification of filename.