Posts Tagged ‘calendar’

Rhaetian calendar

February 17th, 2008 Comments off

So! I have a Rhaetian calendar now.

I rearranged the weeks so that Monday would be the first day of the week and added a week number (à la ISO: week 1 of a year is the first week that contains four days of that calendar year, or equivalently, the first Thursday of the year is in week 1).

Then I had to decide on feasts.

I decided to make Christmas 1 Audunaio, which is 24 December rather than 25, but it seemed like an excuse to say that the (celebration of the) birth of Christ is why the beginning of the year is where it is. That influenced a couple of dates; the circumcision (on the eighth day) and the presentation in the Temple (on the fortieth day) come to mind — oh, and the Annunciation, which I placed on 1 Xanthiko, exactly nine months earlier.

I think I simply translated all the fixed feasts according to common-year calendar equivalences (I picked 2007/2011, which I happened to have handy on my desk).

As for Easter, I decided to put it on the first Sunday on or after 14 Xanthiko.

And as for which feasts to include, I looked up the Eastern Orthodox liturgical calendar and let myself be inspired by their twelve Great Feasts and a couple of other holy days of obligation.

I think the final tally is: Nativity of the Theotokos (8 September = 15 Gorpiaio); Exaltation of the Cross (14 September = 21 Gorpiaio); Presentation of the Theotokos (21 November = 29 Dio); Nativity of Christ (25 December ~ 1 Audunaio); Baptism-Theophany-Epiphany (6 January ~ 13 Audunaio); Presentation of Christ in the Temple (2 February ~ 9 Peritio); Annunciation (25 March ~ 1 Xanthiko); Palm Sunday (Sunday before Easter: 7-13 Xanthiko); Pascha (Good Friday = 12–18 X., Easter Sunday = 14–20 X., Easter Monday = 15–21 X.); Ascension (40th day after Easter: 23-29 Artemisio); PentecostTrinity Sunday (50th day after Easter: 2–8 Daisio) and Monday of the Holy Ghost (51st day after Easter: 3–9 Daisio); Transfiguration (6 August = 12 Loio); Dormition of the Theotokos (15 August = 21 Loio); Peter and Paul (29 June = 5 Panemo); and All Saints (57th day after Easter: 9–15 Daisio).

And, for good measure, the feast day of St. Gall (16 October = 22 Yperberetaio), marked as “National Holiday”.

Categories: Rhaetian Tags: ,

Easter in Rhaetia

February 7th, 2008 Comments off

I’ve been considering what to do about the date of Easter in Rhaetia, since there’s no official word about how WHATL does it and I think the Julian-Gregorian algorithm is extremely complicated.

I think I may just have it always be on the 14th of Ξανθικό, regardless of the day of the week (a different kind of Quartodecimanism…).

When I mentioned that to Stella, she seemed a bit shocked and said that Easter had to be on a Sunday, that it was very symbolic and you couldn’t just move it around the way you could, for example, Christmas. In which case my fallback plan is to have Easter always fall on the third Sunday in Ξανθικό, which will fall in roughly the right period but will stop all that faffing around with Ecclesiastical New Moon and stuff.

“The first Sunday on or after 14 Ξανθικό” might also be an option.

Categories: Rhaetia, WHATL Tags: , , ,

Gregorian-to-WHATL calendar conversion

January 26th, 2008 Comments off

So I tried to make a little program that would convert Gregorian dates to the equivalent WHATL dates.

The first version only used the current date; then I wrote one which would parse a date or a time_t value on the command line. After messing around with it, I eventually got it to work – and found that it gave wrong results in leap years.

Apparently, it was off by one. I had used code from Zefram’s Stardate program, and apparently that assumed that the epoch was 0001-01-01 rather than 0000-01-01.

What annoyed me, too, though was that it only worked during the time period where gmtime() and friends work – on my system, until early 2038.

And since WHATL years and Gregorian years are the same length nearly always (by a fortunate coincidence), you can simply convert from one to another by adding or subtracting four to the year and a certain bias to the date (which depends on the month and whether it’s a leap year or not, and varies between 6 and 9). So I wrote a second version which did that.

After a bit of playing around with that, I think it more or less works now. Pity that I can’t output month and day names in Greek, though (it’s a C command-line program and my command line is not Unicode-aware).

Perhaps I’ll write a Java program or something, though I’m not sure how to integrate it into Java’s existing i18n framework. Presumably a subclass of Calendar and one of DateFormatSymbols. But I don’t see any way to tell DateFormat to use a different calendar, and even SimpleDateFormat can only be passed separate DateFormatSymbols. Where does that leave people using different calendars? Somehow, I think that it’s only half-baked. Perhaps IBM’s ICU will be more amenable.

Or I could just forget about them and just write a little class of my own, which will not have as many features and may have a different interface, but does work with my dates.

Categories: WHATL Tags: ,