Answer:

hour

Answer	Crossword Clue
HOUR	12 to 1, e.g.
HOUR	Day part
HOUR	Lunch break, perhaps

HOUR	One of 24
HOUR	Sixty minutes
HOUR	Shrink's billable segment
HOUR	Consultant's billable unit
HOUR	One of 24 at Le Mans
HOUR	Zero or 11th follower
HOUR	Happy or zero follower
HOUR	"The Children's .." (Longfellow)

HOUR	Happy ..
HOUR	3,600 ticks
HOUR	Sort of glass?
HOUR	Eighth of a workday
HOUR	How long to bake-but check sooner
HOUR	Time of day
HOUR	Cuckoo's announcement
HOUR	Cuckoo's call?

HOUR	Customary time
HOUR	TV drama length
HOUR	Happy ...
HOUR	Zero ...
HOUR	Eleventh ..
HOUR	What the little hand shows
HOUR	Day division
HOUR	"The .. of departure has arrived": Socrates

HOUR	"Spring forward" amount
HOUR	60 minutes
HOUR	TV drama length, often
HOUR	"Fall back" interval
HOUR	Rush ..
HOUR	Time
HOUR	Appointment time
HOUR	Unit of college credit

HOUR	Rush ... (commuters' headache)
HOUR	"Rush ..." (Jackie Chan-Chris Tucker movie)
HOUR	Billing unit, for some
HOUR	Happy ending?
HOUR	Little-hand indication