altFormat'@' not returning correct timestamp

altFormat'@' not returning correct timestamp


I have a simple date picker on a form and I want to set a hidden field
value to the Unix timestamp for a date. Here's the bit of code:
$("#date").datepicker({altField: '#timestamp', altFormat:'@'});
The only problem is that the timestamp is not correct.
If I pick 4/22/2009, for example, the timestamp that is returned is:
1240376400000
The correct timestamp is 1240376400
Has anyone encountered this before? What am I doing wrong?