parsing dates

[Joe Wicentowski]

Hi James,

Got it - now I understand.

Well, if your dates are normalized to yyyy-mm-dd, I'd suggest keeping
them as is in date/@when.  This way, you can set up a range index on
@when, and you can do date comparisons (<, >, =) based on the
searches.  See eXist's documentation on setting up indexing, but I'd
use something like:

<create qname="@when" type="xs:date"/>

This would enable comparison queries like:

let $date := request:get-parameter("date", ("1789-01-01"))
let $query-start-date :=
  if ($date castable as xs:date) then $date cast as xs:date
  else if ($date castable as xs:gYearMonth) then concat($date, '-01')
cast as xs:date
  else concat($date, '-01-01') cast as xs:date
let $query-end-date :=
  if ($date castable as xs:date) then $date cast as xs:date
  else if ($date castable as xs:gYearMonth) then concat($date,
functx:days-in-month($month)) cast as xs:date
  else concat($date, '-12-31') cast as xs:date
for $hit in $docs[tei:date/@when ge $query-start-date and
tei:date/@when le $query-end-date]
...

(for the functx days-in-month function, see
http://www.xqueryfunctions.com/xq/functx_days-in-month.html)

Joe