If you're a little forgetful or have too many holidays and celebrations to remember then perhaps you're in need of a memory aid. I've always found it difficult to keep a diary, mainly because I forget to write in it, as well as forget to read it. And with so many people now keeping all their important appointments and dates in the diary of their mobile, MobileDates seems like a pretty good extra helper.
It comes packed with all the holidays you should be getting off work (up to 2015), which are sorted in order of region (there are 70 countries) and religion. But these are just the basics. You then add new events like birthdays, anniversaries, weddings etc, all the special days you might otherwise miss. It's possible to add little descriptions to this eg what someone might want as a present. This demo is fairly limited but you get the idea.
Basic mobile diary with limited demo