Searching for specimens by day of year

[Tom Humphrey]

I've made a minor update to specimen search by date, so that it's now possible to omit the year and just search by day and month.

While that may not sound to be very useful I think it may help when matching specimens with illegible dates against existing records.
e.g. Hillhouse specimens collected on the 15th May

Date ranges are also possible, so for example you could search for Potentilla specimens collected in June.

Please let me know if anything doesn't work as expected. A known bug is that dates in the years 1800 and 1900 (century non-leap-year exceptions) will be off by 1 day after 28 Feb - the system behaves as though these are leap years. The database overhead of fixing this would be too great to be worthwhile. 29th of Feb also incorrectly matches non-leap 1st March - an error that I plan to correct.