linux: search for files of type *.php recently modified

Add -name '*.php':

find . -type f  -name '*.php' -printf '%TY-%Tm-%Td %TT %p\n' | sort

Note that since the expression is evaluated by find from left to right you must specify the -name test before the -printf action.

See this manpage for details about tests, actions and how find evaluates your expression.

find . -type f -name '*.php' -printf '%TY-%Tm-%Td %TT %p\n' | sort

You can find more options in the manfile of find.