Crossword Clue:

of a period of time Going by

AnswerCrossword Clue
TICKTOCKSound of time going by.
ELAPSINGGoing by, as time
LASTDAYTime for the best deals, maybe, in a going-out-of-business sale
ERALOf a period of time.
HORALOf a period of time.
FUTURESHOCKResult of "too much change in too short a period of time" (Alvin Toffler)