Re: [Gramps-devel] Dates and calendars

[Jochen T. <jo...@re...>]

On Mon, Nov 19, 2001 at 07:42:43AM -0700, Don Allingham wrote:
> Are there any other formats that need to be supported?

Yes, the ISO format: Basically something like "2001-11-19". This format has
many advantages, and I think it should be the internal format used. The
XML file should use a standard format for dates which doesn't depend on
how the dates are entered, because it makes it easier for other people to
parse the XML. The ISO format is more easily parsed than something like
"4 MAR 1971". Also partial dates like "1970" or "1970-06" for June 1970
are easily handled and need no special case.

Also it should be possible to enter ranges of dates, if you know that an
event happened between two dates. And it should be possible to enter
"freeform dates" like "Summer of 1860". This can help for instance if
you date something from a photograph where you can clearly see its summer,
but you don't know anything else.

All this is complex to represent in a user interface. Maybe we could have
something like this: Everywhere where dates can be entered, there is one
input box and one button next to it. You normally enter dates into the
input field in the format that you specified in the preferences. They are
converted to the internal format right after input. If the program didn't
understand what you entered it will warn you. You can write some things
like "ABT 1900" and if the program understands that "ABT" means "ABOUT"
it will note it, otherwise it will complain.

If difficult cases like entering a date range, or when you don't remember
how to enter "ABOUT" dates or so you click on the button, which opens an
extra window. This will allowing entering a start and optional end date,
for each one there is
1) an "about" check box
2) 3 input boxes clearly marked 'year', 'month', 'day', so that there is
   no confusing, which is which
3) a "freeform" box

Other goodies like a calender to choose from, a  French Revolution calendar
calculator can be put in here, too.

But in the end everything will be stored in a simple internal format,
something like:
1903-01-14
ABOUT 1903-01
BETWEEN 1917-04-13 AND 1917-04-14
"Summer 1969"

Here "ABOUT", "BETWEEN", and "AND" are special keywords. And the " around
the "Summer 1969" mark it as freeform. Alternativly there could be two
internal fields for the start and end date. If the end date is empty, there
is only one.

For viewing these would be translated according to language and format
preferences.

Jochen
-- 
Jochen Topf - jo...@re... - http://www.remote.org/jochen/