1// add 1 day to the date above
2$n = date('Y-m-d', strtotime( $d . " +1 days"));
3
4// add 1 month to the date above
5$n = date('Y-m-d', strtotime( $d . " +1 month"));
6
7// add 1 year to the date above
8$n = date('Y-m-d', strtotime( $d . " +1 year"));
9
10// subtract 1 day to the date above
11$n = date('Y-m-d', strtotime( $d . " -1 days"));
12
13// subtract 1 month to the date above
14$n = date('Y-m-d', strtotime( $d . " -1 month"));
15
16// subtract 1 year to the date above
17$n = date('Y-m-d', strtotime( $d . " -1 year"));