One hour

suddenly; at an instant

describes a person's behavior which is inconsistent and / or often changing his / her mind

a moment

at a sudden

one who said something not meant to be spoken; one who slipped with one's words

describes someone who normally doesn't exhibit good behaviour themselves but yet they are quick to point out the mistakes or bad behaviours of others [colloquial]

sometimes

for a while

now and then

Three Kingdoms period

working hours

knock-off time (work)

from time to time

unexpected need

Middle Ages; Mid-Ancient times

during

Nervous

indecisive (slang)

literally: born at the twelfth hour; an expression used to describe those who bring bad luck upon others or those who are unintentionally destructive [written and colloquial]

when

what time? [written]

nowadays

nowadays

how it is nowadays is not the same as how it used to be; the situation is different

break time

when

When and where

according to time given, on time

(slang) in time; on schedule; punctual