I tried to find an explanation and only found a fellow seeker of the truth [0] that also couldn't find the answer [1]. He probably tried to search for it more t

I tried to find an explanation and only found a fellow seeker of the truth [0] that also couldn't find the answer [1]. He probably tried to search for it more than me. I found the Apple source code for ncal [2], but no answers there. Also it is funny that Latin line has the month entered in octal (05). [0] https://hackingtom.blogspot.de/2012/04/date-of-easter-and-ncal.html https://hackingtom.blogspot.de/2012/04/date-of-easter-and-nc... [1] https://xkcd.com/979/ https://xkcd.com/979/ [2] https://opensource.apple.com/source/misc_cmds/misc_cmds-32/ncal/ncal.c https://opensource.apple.com/source/misc_cmds/misc_cmds-32/n...