Thanks to the following site you can find out what was number 1 in the charts in the UK or US on the day you were born:
Of course I already knew, thanks to my trusty Guinness Book of Hit Singles, that for me it was Chirpy chirpy cheep cheep by Scottish vocal/instrumental pop quartet Middle of The Road (who re-located to Italy and were extremely successful across Europe). Not the coolest of songs but very cute and although I don’t have the origianl version I’ve got an excellent cover of it by Lush on the Alvin Lives (in Leeds) compilation album.
I didn’t realise that the US No. 1 was It’s too late by Carole King which is from one of my favourite albums ever: Tapestry