I have written the Jollyday API and I’m interested to know what is so ‘rough’ about it. How can I improve it? Would be great to hear from you. Send me an email to sdiedrichsen@yahoo.de if you like.
By the way. Jollyday is used just the way as the questioner requests it. Please look for yourself.
Cheers, Sven
P.S.: I found a free webservice from Ulrich Hilger which provides detailed worldwide holiday info. Look at api.daybase.eu