how to convert date in timestamp

Monday 03 July 2006 2:10:53 am

Hello all

i have a problem with date conversion,

i have a date set as string, for exemple, today is: "03-07-06" (for french language)
i want to convert this date in timestamp linux in order to compare dates;
How can i do that?

i've defined the PHPOperator (strtotime()) in my template.ini
but the result of this code changes every time :(

{"03-07-2006"|strtotime()} {* or strtotime("03-07-2006")*}

do someone knows why?
please help.
how can i compare date.
PS: an attribute of my class is defined as texfield, that's filled by users as "03-07-2006"