Take a look into this.
You can do something like:
strtotime("+1 week", timestamp);
Where timestamp
is the UNIX timestamp for the start date. You can replace 1 with a variable, and by using a loop you can write a generic function.
Hope this helps.
Edit #1:
Also, you can recur to strtotime() to generate your timestamp:
strtotime("+1 week", strtotime('2014-05-30'));
A possible whole solution would be (untested code):
for ($i = 1; $i <= 4; $i ++) {
strtotime("+" . $i . " week", strtotime('2014-04-25'));
}
4
solved Get n occurrences of a weekday