There is no time of year that they breed....its more like 3 or 4 times a year. What I do is show the female (not before she's a year old/full grown) to the male by holding her outside his cage. This way you can see their reactions without them being able to attack each other.
If the female hisses, rocks back and forth, gapes, inflates her body, darkens her background colors, etc. then she is non-receptive/gravid and she should be put back into her own cage.
If she remains calm, keeps her lighter colors with the yellow splotches an blue dots, does not gape or hiss or rock back and forth....she is receptive and as long as the male reacts properly, they can be put together.
If the male acts aggressively...gapes, inflates his body, holds one hand up near his chin, etc. then he is not seeing the female as a receptive female....and you will have to wait until he behaves in a mating mode.
As Jann has said, there is a lot to consider before breeding!