Want to know what the Nr. 1 hit on any give date was? At least for german charts, you can now check out Nr. 1 Finder.
I did a similar search a while ago to be able to put together a CD with the TOP 20 for the birthdates of my two girls. After finding that the Nr. 1 hit for Fiona’s birthday is by Daniel “Kübelböck, I’ll pass on Nr. 1 Finder, however, and will continue with my previous approach, thank you very much.