In sports, the instruction is to “play to the whistle.” The official blows the whistle, which indicates the end of the play or the game.
It is often possible for something to happen that we think is the end of the play and is not. Our eyes or ears may deceive us into thinking the play is done, and we stop making an effort. Only later do we realize we were mistaken, and if we had kept playing, the outcome might have changed.
Each player is to give a full effort until the one in authority indicates the play is done.
I believe this is a good analogy for the Christian life. As long as God gives us life and breath, we will continue working for his kingdom. We should not quit serving because we feel like our time is up. God is the official and decides when we are done on this earth.
If you woke up today and have the ability to do something for the kingdom of God, then keep going to the whistle, or more Biblically correct, the final trumpet.