[osis-core] div type="date"

[Chris Little]

Good morning everyone,

On day one of the meetings, Steve asked me to look into what would be 
needed to encode a div whose type is a essentially temporal in nature (for 
daily devotionals, lectionaries, timelines, etc.).  I sketched out some 
samples of what would reasonably be needed, and essentially came up with 
something like ISO date format crammed into an osisID.  Steve seemed to 
think it looked okay, so I would propose it as a best practice.

I don't know what the best type would be for these elements, or whether
they should necessarily even be the same type.  Perhaps we should have
divs with type "dailyDevotional", "lectionaryEntry", "timelinePoint", etc.
(just examples--I'm really not married to these names).  The essential
issue is that these divs encode things coded to time/date, so the osisIDs
should have a consistent format.

A simple 365-day, single entry per day devotional would have osisIDs for 
each day's div of a format MM.DD.  Spurgeon's Mornings & Evenings would 
have MM.DD.[AP]M to capture morning vs. evening readings.  (AM/PM isn't 
part of ISO or anything that I know of, but it's a natural extension in 
this situation.)

If you want to encode something based on month/day/hour/minute/seconds, it
would be MM.DD.HH.mm.SS.  Years are 4 digits wide (including zero 
extension where necessary for years < 1000 CE or > 1000 BCE.  If you need 
to encode BCE dates, you should use BCE.YYYY.MM.DD for BCE and 
CE.YYYY.MM.DD for CE dates.

I don't think there's any good reason to constrain people to a particular 
calendar or even to request them to state the calendar they use.

An important aimed-for feature is that, like ISO's format, the osisIDs,
when sorted alphabetically, will also be sorted chronologically.  (So it
is important to specify CE for CE values if you are also using BCE values,
rather than assuming a default.)  BCE sorts before CE.  AM sorts before
PM.  And the digits almost always sort in order.  (The exception,
unfortunately, is that BCE years count down.  I don't see a solution to
that.)

A sample daily devotional in valid OSIS (Spurgeon's Mornings & Evenings) 
is posted at the bottom the documents page at 
http://www.bibletechnologieswg.org/osis/docs/ .

--Chris