Also, the Girlies get cranky and whiny when they don't get their accustomed amount of sleep.
I turned to science for answers on how to get them to sleep on time. They gave me beautifully illustrated diagrams of Sleep Tips:

And Sleep Traps:

The problem is, I've tried ALL of the sleep tips and avoided ALL of the sleep traps – including not mounting a cuckoo clock in their room.
I'm considering finding some sort of child-safe sleeping gas – perhaps administered by umbrella, slipped under the crack of the door. If only the Penguin had been good instead of evil...
I must soldier on bravely, at least until Dilf gets back from New York tomorrow night. At which point I may abandon house.