Hello all,

We have created a TEI P5 schema for marking up Die Musik in Geschichte und
Gegenwart, a large encyclopedia about music. We building a CMS with
MarkLogic to manage the publication (which will be published online in
2017), and I'm running into a problem with indexing dates in MarkLogic.

The (mostly birth- and death-) dates in MGG are not all the same: some have
a month and day, others just a year. So  in the markup, some look like this:

<birth><date when="2001-09-11">11. Sept 2001</date></birth>

while others look like this: <date when="2001">2001</date>

The problem is that is seems that MarkLogic cannot create a range index of
these dates, because they are not all in the same format. The only solution
I have come up with is to add a second attribute that would be normalized
(perhaps a custom @year attribute), but wonder if there are any better
solutions. Anyone have experience with this?