According to Rabbi Nachman of Breslov, it’s ALWAYS time to smile. Taking that proactive mindset and bringing it ‘down to earth’ with something so simple as a facial expression, can have enormous impact on others. (And thus your environment and then back on you!)
What is behind this is knowing that “Everything is in the hands of heaven,” (or,”all things happen for the good to those who love G-d”), so there’s nothing ‘phony’ about it.
This is an example of, “Everywhere where you go, bring the truth of Torah. And when necessary, use words.”