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Karl Palmen's Playing Card Calendar

I've looked at various perpetual calendars that preserve the existing 7 day week, many of which are shown in the calendar reform page. From this, I've come to the conclusion that it would be best to do away with months or second best have months with 4 or 5 whole weeks. If there are no months, then months could be used for a pure lunar calendar, such as my Yerm Lunar Calendar.

Weeks could simply be numbered from 1 to 52 or 53 as with the ISO week numbers. But I find this rather dull, so I brightened it up by using playing cards to represent the weeks. This also enables the suits to represent quarters.

For those who object to playing cards, the quarters and weeks could be given some other name. But playing cards are so familiar that they could form a practical naming system.

I've chosen the suits to be in alphabetical order
Clubs, Diamonds, Hearts, Spades.
In the ISO Deck of the calendar, the cards correspond to the ISO week numbers.
Other decks could be defined for other leapweek rules.

The correspondence between week number and playing card weeks is as shown below:

      Clubs   Diamonds   Hearts  Spades
Ace    01        14        27      40
Two    02        15        28      41
Three  03        16        29      42
Four   04        17        30      43
Five   05        18        31      44
      Clubs   Diamonds   Hearts  Spades
Six    06        19        32      45
Seven  07        20        33      46
Eight  08        21        34      47
Nine   09        22        35      48
Ten    10        23        36      49
      Clubs   Diamonds   Hearts  Spades
Jack   11        24        37      50
Queen  12        25        38      51
King   13        26        39      52

Joker      53

Date example:
1999-08-25 is
Wednesday ISO week 34, therefore
Wednesday Eight of Hearts (ISO Deck)

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I've since found a different playing card calendar at

http://hawk.hama-med.ac.jp/dbk/card_calendar.html
(a nice big graphic shows the year-circle of cards)

It uses Jokers to increase the number of days in a year from 364 to 365 or 366 rather than to provide a 53rd week.

It has been extended to be a lunisolar calendar. Unfortunately, (as of 2001-01-15) the arithmetic is incorrect and the lunar month drifts one week earlier each Metonic cycle
(19 years = 988 weeks, 235 months = 987 weeks).

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