About

This is a hobby blog.

As a child, I found the peculiarities of the calendar troublesome. It just didn’t make sense that December was the 12th month. Nor did the pronounciation of English letters changing by context or word make any sense.

I was inspired by JRR Tolkein’s Lord of the Rings. It’s appendices describe a perpetual calendar used by the hobbits of the shire, and the different phonetic writing systems of the elves and dwarves.

The shire calendar is a perpetual calendar of 12 months of 30 days, in two halves adding a day each for their start and end, split by a summer solstice and the occasional leap day.
Each half comprises 182 days, 26 weeks of 7 days. They start on the first day of the week with a named day; then 6 months of 30 ordinally numbered days each; followed by another named day.
The summer solstice and leap day are intercalary in that they are own days between the halves of the year, and do not occur on a day of the week, nor belong to a month.

It is a truly beautiful inspirational calendar !

Since it was created, the only seriously supported attempt at creating a global perpetual calendar was rejected on the grounds of intercalary days, which were opposed on the basis that some religions would necessarily continue a seven day week unabated.

So any calendar reform must support the seven day week of these religions.
This is ok, as the day of week can act as a checksum to ensure a date has been selected correctly, in an calendar scheme. Further, as the Gregorian has become a widespread civil calendar, any reform should consider making it easy to transition from this and related calendars.

There have been other aspects to consider too, such as numbering and pronunciation. I have been inspired by Edward de Bono who provides an international language neutral pronunciation for decimal digits. In this regard, I have designed a basic duodecimal system to be distinguished from decimal, with the intent to improve it over time through asymmetry.

My current opinions are:

  • a 12 x 120 minute clock mixing use of duodecimal with decimal digits would be an improvement, enabling representation of time of day with the first digit indicating dual hour, the second digit indicating 10 minute period, and then the third digit indicating single minute. This provides a reasonable level of granularity between minute and hour that is useful.
  • a Simpler Roman Calendar with a leap day at the end of year, and moving a day or two to February would be nice. Starting the year in January has become tradition, and is near the winter solstice which chimes with starting a day at midnight. Starting the year in March makes the names of the months correct again, and puts the end of year at the leap day. Overall, I’m undecided.
  • Using cardinal numbers for dates doesn’t feel right yet, having been brought up with ordinal dates. Ordinal times doesn’t feel right either.
    Whether portional numbers can reconcile these is yet to be experienced.
  • As regards leap seconds,
    There’s no need for the leap second precision in day to day life, so I’d usually just ignore it. I’d use a UT1 for simplicity where possible.
    However, UTC specifically has been enshrined into some civil laws and regulations. Where required to map between systems that do and don’t support leap seconds, I’d halve the two final seconds of one into the final second of the other’s day, and record that was the case. This has the benefit of being a reversible mapping keeping events in order, for the small cost of only halving the subsecond precision.
    • for a positive leap second
      map UTC 23:59:59 and 23:59:60 into UT1 23:59:59.
    • for a negative leap second map
      map UT1 23:59:58 and 23:59:59 into UTC 23:59:58.
  • and finally, I favour use of the Holocene epoch (AD/CE + 10,000)
    to make it easier to understand ancient historical dates.

In the end, a lot of this is simply a way to publish my thought experiments, to be able to record and complete the thinking around date and time formats. My hope is that someone finds this useful and interesting.