is a specific kind of: time unit, unit of time.

is a broader term that covers: sidereal hour | man hour, person hour.

has as a part: 30 minutes, half-hour | 15 minutes, quarter-hour | min, minute | quarter.

is a part of: 24-hour interval, day, mean solar day, solar day, twenty-four hour period, twenty-four hours.

derivation: hourly | horary.