Javascript getTime to php date

I have javascript that turns dates in my view to a time string using getTime(). That then is stored as a value for an option in my select form. Once it is passed to php, how do I turn that into a php date?

I have done:

echo date("m/d/Y", '1345618799000');

1345618799000 = Tue Aug 21 2012

Answer

You use PHP’s date() function:

date("Format here (see documentation)", round($_POST["time_field"]/1000));

Updated, thanks Yoshi.