Wilma , Congrats on the spathes. I guess it will depend a lot on the species too. I have had C. pontederiifolia put out 2 spathes (opened) in a span of 1 month. The C.usteriana 'red' that I have has been flowering for a while continuously but it takes about 2 week for the spathe to develop and mature on these.
Since you have had multiple spathes have you tried pollinating them?
Thanks
Bhushan