an hour-long period

timetable

(business) one on one meeting between an employee and a superior

(idiomatic) advance

necessary evil

necessity (quality or state of being necessary, unavoidable, or absolutely requisite)

unnecessary

needlessness

(informal, chiefly in the negative) the slightest amount (in reference to one's knowledge, thought, etc.) / Used other than figuratively or idiomatically: see 一, ミリ.

(Internet slang) first comment; (interjection) first!