Ok, meanwhile I 've understood that we are speaking about seconds.
"1*60*60*24 " = 1 day
"7*60*60*24 " = 7 days

The problem for me is that the routine doesn't calculate well !

It think that perhaps the problem is coming from the fact that I'm using the European date format (dd-mm-yyyy) . so the date that is transmitted to the the script has that format. Perhaps does the script waiting for another date format ?