Where is the food? My food and all water is kept beside their mini barn which is enclosed by fence, when they are let out to forage, most times they come back long before dusk. Mind you i have always herded these guys and everyone who is either bought or hatched here learns this, i can take them from the farthest distances and they'll come in.
I leave food out all day, there is enough there to feed all of them, i think having it by the barn encourages them to be in that area, plus honestly, i had one duck decide she was annoyed by the snow this AM and stayed in awhile lol
It's true though they don't like change, i recently moved the one drake as his stall went to my broody and her brood lol he was displeased at his new arrangement but after a couple days he readjusted.
I usually bring mine into the penned before dark if they are loose/freeranging and put them in right before dark (in the barn) unless the weather is terrible then they'll go in even if daylight.