It began at evening (sunset), the end of the 6th day of creation and is for a 24 hour period ending at sunset on the 7th day. (religion.blogs.cnn.com)
I bet you still believe that the universe was created in 6 24 - hour periods of time. (religion.blogs.cnn.com)
Babies need to be fed at least 10 - 12 times in a 24 hour period in the early weeks and month so it is not ideal to skip feedings or stimulation at night. (lansinoh.com)