I suppose it is inevitable that sunset has become a bit of a cliche for dying, for the end of life, for the "twilight years." I don't think any poet now could use sunset as a metaphor for the end of life - because it has been done so often.
I love Robert Browning's use of "the sunset touch":-
Just when we're safest, there's a sunset-touch,
A fancy from a flower bell, some one's death
A chorus ending from Euripedes, -
And that's enough for fifty hopes and fears
As old and new at once as Nature's self,
To rap and knock and enter in our soul.
Lord Byron (I think from Childe Harold) has a nice little mention too:-
The moon is up - and yet it is not night -
Sunset divides the sky with her - a sea
Of glory streams along the Alpine height
Of blue Friuli's mountain.
(My father quoted this regularly at sunset if anyone was listening!)
And, of course, there is the old Tennyrson quote
Sunset and evening star
and one clear call for me!
And may there be no moaning at the bar
when I put out to sea.
Oh dear - all a bit sad and pessimistic aren't they? Well,, I have to tell you that I don't view sunset like that. Our kitchen window faces due West, so at this time of the year we usually eat our tea to the accompaniment of a glorious sunset if one is available. I thought you might like to see these five different sunset photographs - all taken from our kitchen window - to say that each one fills the sky with beauty is an understatement. Enjoy them.