The Pagan Book Of Hours - Detailed Calendar Information

  1. How does the Solar Calendar work?
  2. What is this "Day out of Time"?
  3. How does the Lunar calendar work?
  4. Are the Greek lunar months traditionally figured this way?
  5. How can I easily convert solar dates to lunar ones, and vice versa?
  6. How do you calculate long and short lunar years?
  7. What is the Hour of the Day, and how is it calculated from the sunrise and sunset times?

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  1. How does the Solar Calendar work?

    The solar calendar follows the standard urban Roman calendar that we use today, with Anglo-Saxon month names in place of the Roman ones as described in the Book of Hours FAQ.

  2. What is this "Day out of Time"?

    Since the version of the lunar calendar that we use starts anew every year on the winter solstice (see the explanation of Lunar Calendar, below), sometimes there are a handful of days that don't fit into either. We call these "days out of time", since they aren't in any lunar month in the calendar. The Solar calendar has one "day out of time"; it's February/Solmonath 29, Leap Day.

  3. How does the Lunar calendar work?

    For our book of hours, we've had to find some way to implement a real lunar calendar, or to be more precise, a lunisolar calendar. It had to be something that kept the lunar year in tune with the seasons (the solar year), and the months synched to the moon. We have settled on this system, based on the one laid out by Linda Kerr.

    The thirteen months are named for the Beth-Luis-Nion Celtic Tree names, each starting on the new moon, with the year ending on the Winter Solstice. Since the solar year is a fair amount shorter than thirteen full lunations, sometimes the first and last month (Beth and Ruis) share one lunar cycle. Roughly three out of five years start short in this way. (If you were using primarily the Greek lunar months, you would simply have 12 full months in "short" years, and add a second Poseideon for a "long" year. There would be no lunar days out of time using this method.)

    Since we're working primarily with the 13 Celtic months, we've chosen to divide the last/first lunation on short years. Ruis ends at the solstice, perhaps in the middle of its lunation, and Beth picks up immediately after and runs until the next new moon, starting Luis. We've chosen to start Beth with Beth 1, then jump directly to the current place in the lunation. This allows the month to start with the ritual that opens Beth, and still be in sync for the Full and New moons. For example, if Ruis 12 was the Winter Solstice in a short year, the next day would be Beth 1, the Day of the Birch Tree. The next day after that would be Beth 14, which is just before the full moon, as it should be. On full or "long" years, Beth starts on the next moon after the Winter Solstice and the days between are considered to be days out of time.

  4. Are the Greek lunar months traditionally figured this way?

    No, but I have not personally researched the topic thoroughly. Hellenic reconstructionists tell me the Greek lunar year is figured with the first moon after the Summer Solstice beginning Hekatombaion, and the additional month added on a fixed schedule. By their system, days are reckoned from sunset to sunset, and the month theoretically begins on the day the new crescent moon is sighted. In practice, it seems, the first of the month was whenever the Archon said it was, giving rise to the practice distinguishing between the "new moon" meaning the first of the month according to the calendar and the Noumenia kata Selene, the new moon according to the moon.

    In practical terms this means the days given by the Book of Hours breviary are consistently a day or two earlier than those given by a Hellenicly reckoned calendar, and occasionally (like in 2006) they are one full lunar cycle late. Our method of irregularly numbering Beth and Ruis and figuring days out of time is not applied. If you want figure lunar calendar by a Hellenic system, check the Hellenic Month Established Per Athens site or this Hellenic Neo-Pagan Calendar.

  5. How can I easily convert solar dates to lunar ones, and vice versa?

    For dates between 2003 and 2020, simply go to the Breviary and select the date in the appropriate drop-down menu. The corresponding date will appear in the other drop-down menu. Both the solar and lunar dates for today are displayed just below that. For the current year, you can look at the Lunar/Solar Listing. This gives the two calendars side by side, but it takes a moment to load.

    For a relatively easy way to work this out on your own, get a listing of the dates of the new moons for the year you are interested in. By our system, the following years have a full lunation for Beth: 2001, 2004, 2006, 2009, 2011, 2015, 2017, 2020, 2022, 2025, 2028. If you are in one of these years, Beth begins on the new moon following the Winter Solstice, and the months follow in sequence from there. If you are not in one of those years, Beth is shortened to share a lunation with Ruis: The first day of Beth is the day after the Winter Solstice, regardless of where in the moon phase you are. After that, the day of the month is still the number of days past the new moon.

  6. How do you calculate long and short lunar years?

    If you look closely, you can see the pattern of long and short years is nearly a cycle of five: long, short, long, short, short. Nearly, but not quite. (A nineteen year cycle works out much closer.) To further complicate things, sometimes (like in 2004 & 2015) the winter solstice falls in the new moon, so even in a "long" year Beth can follow Ruis directly, with no days out. If you find all of this to be entirely too complex, arcane, and messy, you can either take it as a reflection of the nature of the moon, or work out some other way of figuring it.

    If you are interested, this is the system Joshua used to working out the months: Find the date of all the new moons from the period you are interested in, up to the following Winter Solstice. The US Naval Observatory Astronomical Applications Department is a good source. Mark the first lunation that includes the Winter Solstice as 13/Ruis, the one before it is 12/Ngetal, and you number backwards from there to 1/Beth. Do the same for the next year. If you've marked the same lunation as both 1/Beth and 13/Ruis, it is split between the two at the Solstice, and you've got a short year. If not, you've got a long year. Make a note in the margin of the days out of time.

    Alternately, you could use a system that gives the full lunation to Ruis on long years, and not have any days out of time. This isn't the only way to figure the months, but it is the one we've decided to use.

    The Breviary does the lunar-solar calculation automatically, and therre are full year side-by-side listings. Play around with it until it starts to make some kind of sense.

  7. What is the Hour of the Day, and how is it calculated from the sunrise and sunset times?

    The Hours given here are based on and ancient Greek system. Similar to the system of planetary hours used by many ceremonial magicians and astrologers, they are relative to sunrise and sunset and vary by season and location. Check out our page on the Hours for more information. There are twelve hours to the day: one before dawn, own after sunset, and ten through full daylight. The hours are most easily calculated by finding the number of minutes between sunrise and sunset, dividing by ten, and allotting that amount of time for each. The Hour Calculator will automatically do this calculation for you if you enter the sun rise and set times for the day at your location. Sun rise and set times worldwide can be looked up at the Astronomical Applications Department of the US Naval Observatory. The sunrise and sunset times used on the Breviary page are for Hubbardston Mass (W72N42. EST), and may be wildly inaccurate for your location.

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