i thinkv that Time is an illusion,raising from dying!  Humans are the only thing/creatations/etc. in our knowledge of our universe that carry the intellegent cognitive ability to know that we're going to die at some point either young or old. No one lives forever and we are cursed with this knowledge. So as humans obseverve these truths we see the average long term survival ages as well as how between the time of birth and death ,many senarios are potentially able to shorten this time . Nothing through time has made anyone able to live longer than 115yrs and the rarity of this is great. so we keep track of our days because we contiously think and subcontiously know our days are numbered, and how it becomes our obsession that we should keep track of how old we are, how many days in a yr we have,  how many approx yrs we have ultimately against the scale of longest known survival (each different depending on circunstance)but generalized for species. no animal,star ,planet ,bacteria etc. have cognition to keep time or know their demise We humans are cursed with this. Imagine if we lived forever.....time would be a nuisance because whether day/night/season/yr it wouldnt matter to know! Actually  tracking time and having distress mentally/physically/financially     in your eternal existance could/would be dangerous to the state of functionality the individual! in our lives/knowlege everything has a begining and end we cant fathem infinity try for yourself lol have a great evening!