I've talked about this before with other keepers and the general consensus was given optimal conditions, a good quality diet and year round aquatic living, females acclimated to captivity will lay for longer periods than wild newts, but produce less eggs per day. Some years my females will lay from autumn right through to the the following July, especially the captive bred ones, so I guess it depends on the conditions and the individual animals you have.
As far as tail fanning goes, aquatic males seem to be capable of breeding at almost any time of year. They can start fanning after a water change or a sudden temp fluctuation and never seem to lose their breeding colours completely as wild newts do when terrestrial. I guess the main period for breeding in my particular group seems to be December, but there are so many factors that can affect captive groups there are no definitive answers.
