Satoshi entered his birthday as April 5 at the time he registered with [P2P Foundation](http://p2pfoundation.ning.com/m/profile?screenName=0ye0gncqg772o) which was one of the first places where he announced Bitcoin.

The date (April 5) is also a reminder of [Executive Order 6102](https://en.m.wikipedia.org/wiki/Executive_Order_6102) - "forbidding the Hoarding of Gold Coin, Gold Bullion, and Gold Certificates" by US citizens.

The year 1975 is the year, US citizens could finally own gold again.

Happy birthday Satoshi, and thank you for creating Bitcoin (I know you're reading this).