In general, rabbits moult twice a year with the change of seasons in the spring and fall. This process can take a very short time, or may take a number of weeks.Moulting usually begins at the head and and proceeds towards the tail. A baby will moult into an intermediate coat by 12 weeks and into a primeadult coat by 6-8 months.
Rabbits can also go into a moult for a number of other reasons such as change in temperature, change in diet, illness, parasites, pregnancy, hormone imbalance, stress ormedication.
Molting is the natural process of growing a new coat. I've found that the rabbit pellets I feed my rabbit has a direct relation to how well my rabbit molts. Females also shed and pull their fur when pregnant or thinks she's pregnant. My rabbit also used to shed a bed when I'd trim his nails. He trusts me more now. (When Tucker molts, a friend of mine says, "That's where God sewed him together.")
The following is a quote from the book called RABBIT PRODUCTION, 8thEdition, by McNitt /Patton /Lukefahr/ Cheeke. "The pattern of shedding in rabbits has not been definitely established. There is a juvenile molt that begins when a rabbit is about two months old and lasts until it is four to six months of age. Heavy feeding of the young tends to cause the molt at an earlier stage. In addition, there is the annual molt with mature rabbits. The molt varies in time of appearance in different geographical areas."
My rabbit certainly changes coats for the change of temperatures here in the northeast with 4 seasons.
P.S. I just realized that Pamnock answered this question. Sorry Pam. Didn't mean to repeat you!