The time required to do this is referred to as the synodic period of revolution, as opposed to the sidereal period of revolution, which is the time required for a planet to move once around the Sun relative to the stars and is equal to the orbital period.
Mandarin ducks demand very specific breeding sites preferring to nest near water and, ideally, with the nest box accessed from the water, ie: facing a pond or lake, and raised on a platform a metre or more above ground level, reached by a ramp. secure enclosure is essential to keep the Mandarin ducks in and keep out potential predators such as foxes, hawks, crows, and domestic cats and dogs. Pairs usually are allowed a 2m x 2m pen, preferably with a small pond.
The male mandarin duck will molt after the mating season ends from this bright plumage to what is called 'eclipse plumage', of similar greys and browns as the female has year round. https://en.wikipedia.org/wiki/Mandarin_duck