cloudy or rainy weather that continues for several days in a row

A two-part allegorical saying ([[歇后语|歇後語|xie1 hou4 yu3]]) meaning "to have nothing better to do" or "might as well keep busy". The full phrase is "beating the kids on a cloudy day—might as well keep busy"; it originates from the idea of poor laborers who, unable to work outdoors due to rain, would take out their boredom and frustration on their children.