Where should the hyphen be placed? eager for the game to start again, he watched the half time clock.

The hyphen should be placed between the words half time. It should look like this: half-time

Eager for the game to start again, he watched the half-time clock.

Hyphen is a punctuation mark that is used to join words or to separate syllables of a single word. Hyphenation is the name of the process of using hyphens.