Dick, several participants (including myself and Joy in the Pacific NW) have seen multiple-day blooming daylilies when temps are low. In my garden that means daytime highs are no higher than the 60's F. (Kirchhoff's "Wild About Sherry" comes to mind in my garden; I posted two pics somewhere on cubits of the 1st and 2nd day bloom of a single flower.)
I'm just hoping to get info about which parent (i.e., Heavenly Spider Monkey and/or its mate) is passing on these genetics. : )
All the best - Elizabete