Umuganda
I don't know how well it works in practice, how Rwandans feel about it, or if the connection with a colonial past is problematic, but I do like the idea behind this:
Umuganda is a national holiday in Rwanda taking place on the last Saturday of every month for mandatory nationwide community service from 08:00 to 11:00. Participation in Umuganda is required by law; failure to participate can result in a fine.
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