There are fast molters and chickens that take months to complete a molt. Some chickens lose feathers so gradully that you can't really tell they are molting; they just look a tad scruffy. Others seem to drop all their feathers at once and look awful until the new feathers come in.
I have what I call a supersonic molter. Took her a total of about a week to complete the whole process. She now looks great and is back to laying. Her "sisters" are dropping a feather here, a feather there....
So far, my hens have only done the fast molts (Fall/Winter). Each morning it'd look like someone had torn open a feather pillow in their coop - they looked like mangy dogs for a good month...and in cold weather
But my rooster molts slowly.
Other than his tail, he looks pretty much the same year round.