This was working fine yesterday with no changes to the code.
echo date(\"M\", strtotime(\"-3 month\", time()) ); echo date(\"M\", strtotime(\"-2 month\", tim
Try this instead of strtotime:
strtotime
mktime(0, (date("n") - 3 + 12) % 12, 1)
The idea is to take the current month number (date("n")), substract the number of months from it you want (here -3), add 12 to it and then get modulo 12.
date("n")
-3