Humans are the only species that understand the concept of time. Time is an abstraction made by humans to organise events in a line.
Time, and the criteria of time: past and future, before and after do not exist in the realm of nature.
Animals do not keep track of time.
Plants do not keep track of time.
Yet they exist, in a complete different sensorial experience. They experience a world without time, a world without past, a world without future. A world where only what is, exist. A world of pure lasting presence.
Timekeeping belongs only of the human experience.
Time is the abstraction, the concept where all other human created concepts lie upon: past, future, math, physics, history, biology.
Time is the structure and backbone of the human mind.
Without it, there's no mind at all.