On: Cal – Display a Calendar in Your Terminal

[JoshTriplett]

A really fun detail in cal:

    ~$ cal 9 1752
       September 1752
    Su Mo Tu We Th Fr Sa
           1  2 14 15 16
    17 18 19 20 21 22 23
    24 25 26 27 28 29 30

[jaybosamiya → JoshTriplett]

A nice explanation here: https://unix.stackexchange.com/questions/17903/is-cal-broken...

[ashmud → jaybosamiya]

A bit of trivia [1] linked from that discussion about Julian calendar still in use.

[1] https://en.wikipedia.org/wiki/Mount_Athos#Date_and_time_reck...

[Someone → JoshTriplett]

That feature already was in 6th edition UNIX, in 1975: http://man.cat-v.org/unix-6th/6/cal.

I don't think the 5th edition had cal.