Want to make sure this date calcuation is correct

Hai folks,

my date : 2012/9/13

i need to calculate the total number of milliseconds before 60days of above date (my date - 60 days).

i have done the calcuation as follows and i just want to make sure its correct

``````
\$mydate="2012/9/13"
\$expdt=strtotime(\$mydate) - 5184000000; //5184000000 is the number of milliseconds in 60days.

``````

Is the above correct?

Just to ask, are you then going to convert that number back to a date?

hai cups

i have another date will call â€˜your dateâ€™ = â€˜2012/10/13â€™, usually this date is after (greater than) â€˜my dateâ€™.
so i want to calcuate the number of days between â€˜my dateâ€™ and â€˜your dateâ€™

the whole code i am writing will be like this

``````

\$mydate="2012/9/13";
\$yourdate="2012/10/13";
\$mydate=strtotime(\$mydate) - 5184000000; //5184000000 is the number of milliseconds in 60days.
\$yourdate=strtotime(\$yourdate);
\$days=round((\$yourdate-\$mydate) / 86400000); //not tested yet

``````