Time is a human construct, originally started with moment to moment to moment.
Later found that there was a correlation with sun rise and sets. That progressed to modern times where it has been connected to space itself and divided down to the time it takes light to cross an atom.
ALL other animals have no concept of time, just for the moment, they don't plan for future events, yesterday is history.
Technically, time never existed before man. and yes, linear measure never existed until some king had a throne room built to the numbers of length of his foot, and behold the foot. Later the elbow to thumb knuckle came to be known as the cubit.
Perhaps read about historical time keeping devices, right up to our current standard the cesium atom.
Go back before sundials.