Calendar Description
This version of the Julian calendar is commonly used by historians when referring to dates in the first millennium and earlier. The calendar is split into two eras, the Common Era (also known as the Christian Era or AD - Anno Domini) and Before Common Era (also known as Before Christian Era or BC - Before Christ).
Dates Before Common Era end on the 31st December year 1 BCE and the years are counted backwards from this point for all previous years. The Common Era start the next day, the 1st January, year 1 CE and continues until the present day. Thus, years are always positive and there is no year zero. Leap years follow the same rules as the Julian calendar scheme.
Use Case
For dates in the Common Era this scheme is the same as the Julian scheme, which includes the period for when it was in contemporary use. As this scheme requires an additional field (BCE or CE), the simpler Julian scheme is preferred. However, when dealing with dates before the second millennium it is convenient for Historians to use a single scheme.
Definition
| Record - Default order | |||||
|---|---|---|---|---|---|
| year | month | day | wday | ce | ceyear |
| Record - Ranking order | |||||
|---|---|---|---|---|---|
| ce | ceyear | month | day | wday | year |
| Historic Era | |||
|---|---|---|---|
| Number | Era | Abbrev. | Range |
| 0 | Before Common Era | BCE | past ~ j:dmy# 31 Dec 0 |
| 1 | Common Era | CE | j:dmy# 1 Jan 1 ~ future |
The Julian Common Era scheme is a variation of the Julian scheme and has the same definition except that it includes the optional fields ce and ceyear.
The Record consists of three Fields named year,
month and day and the optional Field wday
- these are as described for the Julian scheme.
As stated, the record also includes the optional Fields ce and ceyear.
These fields are ranked into the order shown in the Record.
The ce field has the value 0 for all values of year less than one,
and the value 1 for all other values of year.
The ceyear field has the value -year + 1
for all values of year less than one,
and the value year for all other values.
| jce | ce | ceyear | month | day |
|---|---|---|---|---|
| 1 | 1 | 1 | 1 |
| jdn | day |
|---|---|
| 1721424 |
Script
| Default Script |
|---|
| lexicon jce { name "Historic Era"; fieldname ce; lang en; pseudo CommonEra, CE; tokens { 0, "Before Common Era", "BCE"; 1, "Common Era", "CE"; } } grammar jce { optional wday, ce, ceyear; rank ce, ceyear, month, day; lexicons m, w, jce; alias field { WDay, wday; Day, day; Month, month; Year, ceyear; CEra, ce; } alias pseudo { w, WDay; dd, Day; mm, Month; yyyy, Year; } alias unit { d, day; m, month; y, year; w, week; } format dmy, "(Day) |(Month:m:a) |(Year) |(CEra:jce:a=CE)"; format wdmy, "(WDay:w:a) |(Day) |(Month:m:a) |(Year) |(CEra:jce:a=CE)"; format out { output "(Day::os) |(Month:m) |(Year) |(CEra:jce:a)"; } format full { output "(WDay:w) |(Day::os) |(Month:m) |(Year) |(CEra:jce)"; } format "dmy+", "(Day) |(Month:m) |(Year) |(CEra:jce=CE)"; format "wdmy+", "(WDay:w) |(Day) |(Month:m) |(Year) |(CEra:jce=CE)"; format mdy, "(Month:m:a) |(Day), |(Year) |(CEra:jce:a=CE)"; format ymd, "(Year)|(CEra:jce:a=CE)|:(Month:m:a)|:(Day)"; pref dmy; } scheme jce { name "Julian Common Era"; base julian; grammar jce; } |
The script makes use of the Optional Field wday
to output weekdays and so it requires the 7 Day Week lexicon "w".
It also requires the Julian month lexicon "m".
