between 1st and 2nd comma, substract ..how?

[ohdang888]

ok so i want to take this (stored in a variable):

2010,02,15,23,59,59

 

and make it this:

2010,01,15,23,59,59

 

in other words, i want to take the value between the 1st and 2nd comma, and subtract it by 1.

 

How would i go about doing this?

 

Thanks

[jl5501]

$var1 = '2010,02,15,23,59,59';
$var1_arr = explode(",",$var1);
$var1_arr[1] = (int) $var1_arr[1] - 1;
$var1 = implode(",",$var1_arr);