6*6*10 is a perennial solar calendar with:

  • 6 months per year
  • 6 weeks per month
  • 10 days per week

Every month ends with a blank day, with the exception of the last month in non-leap years. Blank days are intercalary days and can be treated as holidays.

One Month
Week Days
W0 00 01 02 03 04 05 06 07 08 09
W1 10 11 12 13 14 15 16 17 18 19
W2 20 21 22 23 24 25 26 27 28 29
W3 30 31 32 33 34 35 36 37 38 39
W4 40 41 42 43 44 45 46 47 48 49
W5 50 51 52 53 54 55 56 57 58 59
Blank 60

Nice attributes of the 6*6*10 calendar[edit | edit source]

The units are regular:

  • Every year is the same (except leap years).
  • Every month is the same (in leap years).

A regular calendar simplifies scheduling.

Days of month are decimal zero-based numbering:

  • One's place corresponds to the weekday number.
  • Ten's place corresponds to the month's week number.

Thus dates are easy to compute and visualize in your head.

The units are divisible (ignoring blank days):

  • All units are divisible by half – ½ year, ½ month, ½ week.
  • All units are divisible a second way – ⅓ year, ⅓ month, ⅕ week.

Divisibility allows flexibility. For example, if weeks (10 days) is too long for a recurring schedule, then use a half weeks (5 days).

Month-week-day format:

  • Explicitly states the week number and weekday (no need to consult a calendar to look up the weekday).
  • MWD consumes only three digits (which is more compact than Gregorian's MMDD four digits).
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