count-down/ˈkoun(t)ˌdoun /
Noun
an act involving counting backwards to zero "The countdown reached ten seconds and I could almost hear an invisible crescendo of stirring background music." Gene Cernan (1934-2017) the short period of time prior to a major event "Our lives have a countdown clock that we can't see; mine reminds me to only do work that matters." Donald Miller (1971-)