Two Suns in the Sunset" is the final song on Pink Floyd's 1983 concept album, The Final Cut. Partway through the song, the lyric "the sun is in the east, even though the day is done" is a metaphor referring to the glowing fireball of a nuclear explosion.
The Final Cut's main proponent was the band's bass player and songwriting frontman, Roger Waters, previously a chair of the youth branch of the Campaign for Nuclear…
In my rear view mirror the sun is going down
Sinking behind bridges in the road
I think of all the good things that we have left undone
And I suffer premonitions, confirm suspicions