1) Class hours 2) Divisions of a hockey game 3) Dots 4) Drops, IE, at intervals 5) Game segments 6) Hockey game divisions 7) Hockey threesome 8) Lunch and study hall 9) Punctuation marks 10) Sentence enders 11) Sentence stoppers 12) Sentence-ending marks 13) Some book ends 14) Stages of history 15) The Jazz Era, and others 1) Dots 2) Ends 3) Epochs 4) Eras 5) Spells 
the segments of time into which a game is divided; a regulation game played by adults consists of two 45-minutes halves.
Discrete intervals of time. The word period generally refers either to the interval of the entire fo
[Ice Hockey] three 20-minute playing intervals separated by two intermissions.[Soccer] the segments of time into which a game is divided; a regulation game played by adults consists of two 45-minutes halves.