preg_match and dates

I have absolutely no control over the source file. The source file is an xml file (er, sort of, it doesn't follow any particular DTD) and has a tag called VERBATIM_DATE in each record - looks to be required in their output as every record so far has it, but w/o a DTD hard to know - time of day, on the other hand, is not required and sometimes (usually) the tag missing. Here's the beauty - VERBATIM_DATE in the same xml file uses multiple different formats. IE - 12 March 1945 14 Mar 1967 Apr 1999 12-03-2005 Before 1904 Winter or Spring 1977 etc. It does seem that if there is a day, the day is always first - but sometimes it has a space as a delimiter, - as delimiter, and sometimes it has both - IE 10-15 Dec 1934 12 March-03 April 1956 What I'm trying to do is write a preg matches for each case I come across - if it matches the preg, it then parses according to the pattern to get me an acceptable YYYY-MM-DD (not sure how I'll deal with the season case yet ... but I'm serious, that kind of thing in there several times) To at least get started though, is there a wildcard defined that says match a month? IE /^([0-9]{2})[\s-](MONTH_MATCH)[\s-]([0-9]{4,4}$/ where MONTH is some special magic that matches Mar March Apr April etc. ? If you must know - it's data from a biology vertebrate museum. Thousands of records may match a given query. Most of them look fairly easily parsable and it does look like when a day is specified, it is always first and year is always last. The data is needed by me, so I'm planning on having the script die if it comes across a date I don't have a regex to parse before it does anything so I can add appropriate regex as necessary, but damn - you'd think a vertebrate museum would have cleaned up their DB somewhat.