ATC
around the clock
a.c.
before meals
c.c.
with meals
p.c.
after meals
a.m.
morning
p.m.
afternoon, evening
h.s.
at bedtime
p.r.n.
as needed
q
each, every
h, hr.
hour (2 sigs)
q.d.
each day
b.i.d.
twice a day
t.i.d.
three a day
q.i.d.
four a day
q.a.d.
every other day (quoque alternis die)
q.o.d.
every other day
q.a.m.
every day before noon (every morning)
q.p.m.
every day after noon (every evening)
q.h.
every hour
q.h.s.
every night at bedtime
q2h
every two hours
q4h
every four hours
q6h
every six hours
q8h
every eight hours
q12h
every twelve hours
STAT
immediately
x
times
y
year