I have completed map 851 and now there is a 4 day 12 hour delay until new maps are available, this..

You can still play old chapters for free. Playing in between new releases is a good way to build up your supply of materials and also to find more compasses and get more coin for your bank as well as energy. You can also sit it out and wait for Thursday. I stopped playing and let the game get 20 chapters ahead of me so I did not have this issue anymore. Its annoying. An added bonus was saving all the energy. I have built an energy bank of 56,000! Yes, you read it right. I will absolutely never run out of energy!