The program that you likely know as "cal" is itself a clone, named "ncal" and written by Wolfgang Helbig in the 1990s. It was preceded by a clone written for B

The program that you likely know as "cal" is itself a clone, named "ncal" and written by Wolfgang Helbig in the 1990s. It was preceded by a clone written for BSD by Kim Letkeman in 1989, which was in turn a replacement for a "cal" written by Bill Joy. * https://svnweb.freebsd.org/csrg/usr.bin/cal/cal.c?view=log https://svnweb.freebsd.org/csrg/usr.bin/cal/cal.c?view=log * https://manpages.debian.org/buster/bsdmainutils/ncal.1.en.html https://manpages.debian.org/buster/bsdmainutils/ncal.1.en.ht...