The Tinker and the Timestream
Novella 18,141 words Recommended by 4 award/anthology sources
"The Taghrib Colony had existed for almost two hundred years, and all that time it had been waiting to die. Then one night Rustem, tinker of Biskra, discovered a nova in the sky. The beautiful, deadly sun had just gone down, and the twilit air was intoxicating with the breath of plants exhaling in relief when Rustem climbed the clock tower to make his nightly measurements."
Quasar links out; the story lives on Analog, where the author gets the click.