American flags, except in exceptional circumstances, aren't supposed to be up if unlit (which means if you don't have artificial lighting on them all the time, they come down at sundown) and they aren't supposed to be up in rain and storms for their own protection. So in theory, they go up and down a lot. At encampments etc. they're usually ceremonially raised/lowered at dawn/dusk, and at institutions and workplaces that fly them they're usually raised/lowered as part of opening and closing a building for the day. (Australia seems to have similar rules, at least for dawn/dusk.)

Households that fly flags in theory also do this; often it works out as we put it up only when we're at home and awake (which is part of the reason they're traditional in tourist towns particularly, it's a signal the owners of a vacation home are in town and around.) Leaving them up all the time regardless of the guidelines therefore becomes a symbol of wanting to signal patriotism as long as it's not inconvenient.