Policy must change over month of games (7)
I believe the answer is:
olympic
'policy must change over month of games' is the definition.
I can't tell whether this definition defines the answer.
'policy must change over month' is the wordplay.
'must change' indicates an anagram (I've seen this in other clues).
'over' indicates putting letters inside.
'month' becomes 'm' (standard abbreviation).
'policy' is an anagram of 'olypic'.
'olypic' going around 'm' is 'OLYMPIC'.
Can you help me to learn more?
(Other definitions for olympic that I've seen before include "These games are held every four years" , "of certain events" , "Games, quadrennial in occurrence" , "Of a worldwide sporting movement" , "International sporting event" .)