Umuganda

On the last Saturday of every month, between 8:00 and 11:00, at least one person between the ages of 18 and 65 in every Rwandan household must get outside and clean, fix or do maintenance work. Umuganda, a Kinyarwanda word that can be roughly translated as community service, is part of Rwanda's heritage. I am in favor of the nation-wide ritual of pitching in because it's a good practice.

Useful link:
http://www.bbc.com/travel/story/20200105-the-most-inviting-city-in-africa