Well, time is complicated, but not for reasons that really matter to 99.95% of engineers (relativity and such). At its most basic level, Time is really just a monotonically increasing counter of seconds (or ms or ns or whatever). That's it.
The problem is really the cultural and societal layers on top of it. That's not Time's fault, its Our fault. A "Day" has to be 1 rotation of the earth around its axis, a "Year" has to be 1 rotation of the earth around the sun, etc.
Every unit of time at the Second and below is Simple. Every layer above it is Complex, including the counter of seconds from any date in the past, because Humans are Complex, not because Time is Complex. If we stopped caring that it always has to be cold in Winter (in the US) or that 7am is always morning (well, sunrise changes w.r.t both time and location), or that days are always (usually) 86400 seconds long, our interactions with time would be much simpler.
And, really, given that EVERY SINGLE UNIT above the second has not just some but many special case rules that are instantly confusing, maybe we should stop caring so much.
There's definitely something to be said about overengineering though. No human is going to notice if the clocks all drift together by 1 second per year.
Seconds are only Simple if they are defined as such. If they are defined as a subdivision of the day, then they need to be rebound to the slowing rotation of the Earth as the Earth slows and as relativistic differences due to altitude come into play.
If the second uses some other definition, you still need some centralized authority to define its length, for the same reason that it’s measurement will drift depending on your reference frame.
The problem is really the cultural and societal layers on top of it. That's not Time's fault, its Our fault. A "Day" has to be 1 rotation of the earth around its axis, a "Year" has to be 1 rotation of the earth around the sun, etc.
Every unit of time at the Second and below is Simple. Every layer above it is Complex, including the counter of seconds from any date in the past, because Humans are Complex, not because Time is Complex. If we stopped caring that it always has to be cold in Winter (in the US) or that 7am is always morning (well, sunrise changes w.r.t both time and location), or that days are always (usually) 86400 seconds long, our interactions with time would be much simpler.
And, really, given that EVERY SINGLE UNIT above the second has not just some but many special case rules that are instantly confusing, maybe we should stop caring so much.