My chicks are 10 weeks old and now that they are FINALLY putting theirselves to bed at night in the coop, I have been locking them in. The problem is that they are going to bed about 5:30pm now because of the time change and it getting dark. I do not get out there in the mornings until about 8 or 8:30 to let them out. On nights that temps are in the 40s should I leave the door open to the run or close them up. They are in their for about 15 hours without food or water.......is that ok?