cal is a cal(1) clone.

ncal is also available.

 (cal -c it 10 1582)     (cal -c gb 9 1752)      (cal -mt 4 2000)

    October 1582           September 1752            April 2000
 S  M Tu  W Th  F  S     S  M Tu  W Th  F  S     M     3 10 17 24
    1  2  3  4 15 16           1  2 14 15 16    Tu     4 11 18 25
17 18 19 20 21 22 23    17 18 19 20 21 22 23     W     5 12 19 26
24 25 26 27 28 29 30    24 25 26 27 28 29 30    Th     6 13 20 27
31                                               F     7 14 21 28
                                                 S  1  8 15 22 29
                                                 S  2  9 16 23 30

The original cal appeared at Unix early age as cal(6) which is written by Ken Thompson, I think. Unix V1 cal(6)



"Calendrical" module is for calendrical calculations.

Most of this was translated by me from “Calendrical Calculations” and “Calendrical Calculations, II: Three Historical Calendars”.

In addition to the above, I also wrote code for a few calendars.

This module supports the following calendars:

Gregorian (New Style), Week Date ("ISO"), Julian (Old Style), Islamic (Moslem), Hebrew (Jewish), Mayan, French Revolutionary, Old Hindu, Achelis', Coptic, Ethiopian, Jalali, Bahá'í, Indian National, Revised Bengali, Nanakshahi and Kyūreki

NOTE: The correlation of Mayan Long Count is GMT (584,283). Jalali is not complete yet. Indian National, Revised Bengali and Nanakshahi are now experimental. This module represents Japanese traditional calendar ("Kyūreki") in Gregorian year. This module handles Julian day number and Modified Julian daynumber as "chronological" ones.

There are Ruby and Python version available.

rubyist tar.gzrubyist gempythonian tar.gz


This simple script creates iCalendar file from's race calendar.

cwrc.rbSee Race Calendar 2015 via fruux


date/holiday provides methods about determination of holidays.



This is an ensemble file of NI Reaktor 4, which determines Easter sunday of the given year. Reaktor 5 and Reaktor 5 Player (Free) also can open this.

screenshot of easter-ens


gopt is a simple wrapper of getoptlong.


"Just another Ruby hacker,"

An ancient game - "Just another Ruby hacker," (for ruby 1.8)

     'nyae  kcrRt,auorhh e stJub').


0.step(72,3){|i|$><<'J huhesartc  kRaeunrbo,yt'[i%25..i%25]}

  each_with_index{|x,i| $><<(x^'Begin landing your troops'[i]).chr}

$><<[[[['J'],[[[['u']]],[['s']]]]],[['t',[[[[' ']],'a']]]],['n'],[[['o']],[
[['t']],'h']],[[['e'],['r']]],[[[[' ']],['R']]],[[[['u']]],['b']],[[[['y'],
[' ']]]],[[['h',[[[[['a']]]],[['c']]],'k']]],[[['e']]],[[[['r']]],[[',']]]]

'Jluisptf lainpoftlhieprf lRiupbfyl ihpafclkiepr,'.gsub(/[flip]/,'flap'*0).display

('b'*0+'J'+'u'+'y'*0+'s'+'t'+' '+'v'*0+
 'a'+'n'+'o'+'p'*0+'t'+'h'+'e'+'r'+' '+
 'c'*0+'R'+'i'*0+'u'+'j'*0+'b'+'y'+' '+

25.times{|i|$><<('BqSt ajmthe2 BubY HA#iep('[i]|'Heq4 `.OthER Rq`9 hackEr,'[i]).chr}


This is an "OpenSound Control" module. This is an implementation of "OpenSound Control" (OSC) that is a protocol of application-level for especially musical interest.



This is a calendar module. The original core code from SDN calendar library which is written by Scott E. Lee.

This module supports the following calendars:

Gregorian, Julian, French Republican, Jewish

rubyist tar.gzrubyist gempythonian tar.gzthe original source


This is a “Standard MIDI File” module. This module handles encoding and decoding about "Standard MIDI File" (SMF).



This simple script creates iCalendar file from Union Cycliste Internationale (UCI) published .xls file. Actually, this script handles .csv file which converted with format converter such as ssconvert(1). UCI also published iCalendar files. But they are junks.

ucirc.rbSee Road 2015 via fruux


date2-4.0.19.tar.gzdate2-4.0.19.gemdate4-0.1.30.tar.gzdate4-0.1.30.gem dvipc-1.1.1.tar.gz gtkcal.rb isbn-1.1.tar.gz luna.rbnqt.rb nucomp-0.2.2.tar.gznurat-0.2.2.tar.gznuby-1.86.004.tar.gz nutime-0.0.4.tar.gznutime-0.0.4.gem once-2.4.tar.gzonce-2.4.gem pluto-1.5.9.tar.gz rar.rar sspbm-2.1.tar.gz wc.rb