My answer was going to be by the sun. If I were blind, I could still feel the sun on my skin, and through that feeling, know the time.
Other than the sun, I would measure time by the growth and interests of my children, and my children's children.
A psychological progression. Although, not necessarily linear. Time is probably a mind thing mostly
It's already been written. Time would be measured by the journey of the sun. I chose the word "journey" for good reason. The root word is "jour" which is day in French.
As a 14 year old desperate for pocket money I'd work all Summer on a cash-crop farm. Day after day of non-stop howing and pruning. By the start of August I discovered I could tell the time with 3-4 minutes accuracy by observing the sun and dead-reckoning its position in relation to fixed ob
That's what I know of time via personal observation. In truth, I know it was created by God when he envisioned "night and day". God existed for all eternity and the only way the human mind can come close to comprehending that- is to remember that God created time and he is not subject to it.
If we were not aware of time--we'd lose perspective and many other things.
As I grow older I'm aware my time for getting things done, grows short and I recall how quickly and easily a decade passes. In 7 months it'll be the 10th anniversary of 9/11. That was alarmingly fast.
By stable processes, eg. oscillations of the cesium atom. You could also use the speed of light, to measure time by the distance it travels (speed of light is constant).
But, I think you are alluding to the question, what if it was impossible to measure time? Then applying the usual principles of physics in such a circumstance the concept of time should not enter in the desc
What is apparent though in the case when you can measure time is that it is a counting of events, where events are usually a collection of particle interactions. Thus in a universe where no particles could interact time doesn't exist, because an unmeasurable quantity is useless.