Hi Patricia, you want comments on your post so here's mine:
As you know, I was Moderator on the Animal & Wildlife Forum, on Wet Canvas for many years and this Format for the Challenge there, (and here,) was mine. Members loved seeing the photos for the Monthly Challenge posted every month and they wanted the date chosen (the 20th) so everyone could have the anticipation and excitement of posting their "take" on the photos at the same time. That's why a monthly "Reveal" date was chosen. And this Challenge was one of the most popular on Wet Canvas. BUT, as has been already mentioned, on the new All Media Art Events, this is not Wet Canvas and this is YOUR Challenge. So I think you can change the "Guidlines", to what you want the Challenge to be! As a footnote: I loved making a Gallery every month of the entries - it gave me a chance to have a really good look at the entries and werent they wonderful every month! But times change and we have to go with what Creative Spark members want - and on All Media they have done away with the photos option and are now going with "prompts". As popular? Only time will tell.