Calendar Description - Scheme h
The Hebrew calendar, also known as the Jewish calendar, is a lunisolar arithmetical calendar based on the 19 year Metonic cycle. In 7 of the 19 years, an extra month, named "Adar I" is added before "Adar" (and "Adar" is renamed "Adar II").
Prior to using the this calendar, a observational system was used, both in determining the start of the lunar month and, by using natural phenomena, in adding the intercalated month. The Metonic cycle may have used to check and confirm the observations, but it was not until Hillel II in the fourth century CE that this replaced the observational system. The rules for calculations slowly evolved until around the 12th century, when the calendar described here was formulated.
Use Case
The mathematics of the calendar is commonly attributed Hillel II in the fourth century CE. From then it slowly evolved until it reached its current form in approximately the 12th century.
- Social records within Jewish communities worldwide.
- Israel since its inception in 1948.
Definition
| Record - Default order | |||||
|---|---|---|---|---|---|
| year | month | day | cmonth | wsday | |
| Record - Ranking order | |||||
|---|---|---|---|---|---|
| year | cmonth | day | wsday | month | |
| Month Names - Lexicons hm & hcm | |||||
|---|---|---|---|---|---|
| Number | Name | Note | |||
| Full | Abrev. | Alternative | |||
| 7 | Tishrei | Tsh | Tishri | 30 | |
| 8 | Cheshvan | Csh | Marheshvan, Heshvan | 29 | 30 days in complete year |
| 9 | Kislev | Ksl | 30 | 29 days in deficient year | |
| 10 | Tevet | Tvt | 29 | ||
| 11 | Shevat | Shv | Shvat | 30 | |
| 12 | Adar | Adr | 29 | Common year only. | |
| 14 | Adar I | Ads | 30 | Leap year only. Lexicon hcm only | |
| 13 | Adar II | Ads | 29 | Leap year only. | |
| 1 | Nissan | Nsn | Nisan | 30 | |
| 2 | Iyar | Iyr | Iyyar | 29 | |
| 3 | Sivan | Svn | 30 | ||
| 4 | Tammuz | Tmz | Tamaz | 29 | |
| 5 | Av | Aav | 30 | ||
| 6 | Elul | Ell | 29 | ||
| Week Names - Lexicon hw | ||
|---|---|---|
| Number | Name | |
| Full | Abrev. | |
| 1 | Yom Rishon | Rish |
| 2 | Yom Sheni | Shen |
| 3 | Yom Shelishi | Shel |
| 4 | Yom Revi'i | Revi |
| 5 | Yom Hamishi | Hami |
| 6 | Yom Shishi | Shis |
| 7 | Yom Shabbat | Shab |
The year length is one of 353, 354, 355, 383, 384 or 385 days, and average approximately 365.24682 days. Days start at sunset, the conversion here is for midday.
Months are linked to the Lunar cycle starting near the new moon and are 29 or 30 days long.
Regular years consist of 12 months and leap years of 13 months. Leap years occur on the 3rd, 6th, 8th, 11th, 14th, 17th and 19th years of a 19 year cycle beginning in year 1.
In a common year, the months are numbered 1 to 12 In a leap year an additional 30 day month, traditionally unnumbered, is inserted between months 11 and 12. However, in this scheme, the additional month is numbered 12 and the existing 12th month is renumbered 13. The length of each month is shown in the given table.
The length of a nominal regular year or leap year is 354 or 384 days, the length of a complete year is 355 or 385 days whilst that of a deficient year is 353 or 383 days.
In both common and leap years, the year count in increased on the 1st day of the 7th month.
The New Year (the day the year count is increased) occurs on the 1st day of the 7th month.
The calendar is also linked to the 7 day week, with the days numbered 1 to 7, and with Sunday equal to day 1.
The following rules are used to determine when the New Year falls and thus, the length of the year.
- If the time of the new moon is at midday or after then the New Year is delayed by one day.
- If the New Year were to fall on a Sunday, Wednesday or Friday then the New Year is delayed by one day or 2 days if combined with the previous rule.
- If the previous rules combine to increase the length of the following year to 356 days, the current New Year is delayed by a day.
- If the previous rules combine to decrease the length of the previous year to 382 days, the current New Year is delayed by a day.
| h | year | month | day |
|---|---|---|---|
| 1 | 7 | 1 |
| j | year | month | day |
|---|---|---|---|
| -3760 | 10 | 7 |
| jdn | day |
|---|---|
| 347998 |
Formats
One problem with formatting the month name, is the difference in the Adar month name in common and leap years. The 12th month name is "Adar" in a common year and "Adar I" in a leap year. We cope with this by creating a calculated field named cmonth. For a cmonth field, the 12th month is renumbered to 14th in a leap year. In all other respects, the cmonth field is the same as the month field.
The formats supplied with this scheme.
| Formats - Grammar h | |||||
|---|---|---|---|---|---|
| Code | Rule | Pseudo | Example | Note | |
| dmy_a | text | Input: day cmonth year Output: dd Mon yyyy | 30 Adf 5784 29 Ads 5784 29 Adr 5785 | S | |
| dmy | text | Input: day cmonth year Output: dd Month yyyy | 30 Adar I 5784 29 Adar II 5784 29 Adar 5785 | D, S | |
| dmy- | text | Input: day month year Output: dd mm yyyy | 30 12 5784 29 13 5784 29 12 5785 | S | |
| wdmy | text | Input: wsday day cmonth year Output: Weekday dd Month yyyy | Yom Rishon 30 Adar I 5784 Yom Sheni 29 Adar II 5784 Yom Shabbat 29 Adar 5785 | ||
| ymd | text | Input: year cmonth day Output: yyyy Month dd | 5784 Adar I 30 5784 Adar II 29 5785 Adar 29 | S | |
| ymd- | text | Input: year month day Output: yyyy mm dd | 5784 12 30 5784 13 29 5785 12 29 | S | |
| gedcom | text | Input: day month year Output: dd MON yyyy | 30 ADR 5784 29 ADS 5784 29 ADR 5785 | S | |
| def | text | Input: year month day cmonth Output: yyyy mm dd mm | 5784 12 30 14 5784 13 29 13 5785 12 29 12 | H | |
| u | unit | Input: 9y 9m 9d 9cm Output: 9y 9m 9d 9cm | 5784y 12m 30d 14cm 5784y 13m 29d 13cm 5785y 12m 29d 12cm | H | |
| Notes: D = Default, H = Hidden. Example based on jdn# 2460380, 2460409 and 2460764 | |||||
Script
| Script - Module hics:hebrew |
|---|
| lexicon hm { name "Month names"; fieldname month; lang en; pseudo Month, Mon; tokens { 1, "Nissan", "Nsn", "Nisan"; 2, "Iyar", "Iyr", "Iyyar"; 3, "Sivan", "Svn"; 4, "Tammuz", "Tmz", "Tamaz"; 5, "Av", "Aav"; 6, "Elul", "Ell"; 7, "Tishrei", "Tsh", "Tishri"; 8, "Cheshvan", "Csh", "Marheshvan", "Heshvan"; 9, "Kislev", "Ksl"; 10, "Tevet", "Tvt"; 11, "Shevat", "Shv", "Shvat"; 12, "Adar", "Adr"; 13, "Adar II", "Ads"; } } lexicon hcm { name "Complete Month names"; fieldname cmonth; inherit hm; tokens { 14, "Adar I", "Adf"; } } lexicon hw { name "Weekday names"; fieldname wsday; // Note: Days are numbered from Sunday, unlike "wday". lang en; pseudo Weekday, WDay; tokens { 1, "Yom Rishon", "Rish"; // Sunday 2, "Yom Sheni", "Shen"; // Monday 3, "Yom Shelishi", "Shel"; // Tuesday 4, "Yom Revi'i", "Revi"; // Wednesday 5, "Yom Hamishi", "Hami"; // Thursday 6, "Yom Shishi", "Shis"; // Friday 7, "Yom Shabbat", "Shab"; // Saturday } } grammar h { name "Hebrew"; fields year month day; calculated cmonth; optional wsday; rank year cmonth day; lexicons hm, hcm, hw; alias pseudo { w wsday; dd day; mm month; mm cmonth; yyyy year; } alias unit { d day; m month; y year; cm cmonth; } function calc_cmonth { cmonth = @if( month=12 and @leapyear.hebrew(year), 14, month ); result = this; } function calc_month { month = @if( cmonth=14, 12, cmonth ); result = this; } use { calculate calc_cmonth; from:text calc_month; } format dmy_a "{day} |{cmonth:hcm:a} |{year}"; format dmy "{day} |{cmonth:hcm} |{year}"; format "dmy-" { inout "{day} |{month} |{year}"; rank year month day; use:in calc_cmonth; } format wdmy "{wsday:hw} |{day} |{cmonth:hcm} |{year}"; format ymd "{year}| {cmonth:hcm}| {day}"; format "ymd-" { inout "{year}| {month}| {day}"; rank year month day; use:in calc_cmonth; } format gedcom { inout "{day} |{month:hm:a:u} |{year}"; rank year month day; use:in calc_cmonth; } preferred dmy; } scheme h { name "Hebrew"; base hebrew; grammar h; } |
The Month name abreviations are those used by the GEDCOM standard version 5.5.1 Page 53 (PDF).
Note, the use of optional field "wsday" in which the week starts on Sunday (day 1).
