I've got an encrypted wallet and want to unlock it "until next reboot."

So I tried setting a timeout of 10 years (315360000 seconds):

bitcoind walletpassphrase "wouldn't you like to know" 315360000

... but when I check the unlocked_until time it is unlocked only until the end of the month :

bitcoind getinfo  
"unlocked_until" : 1333159764,

1333159764 is 2012-03-31 02:09:24 GMT