ILs regularly show up unannounced in the evening, 6.30-7.30pm just before or at DC bedtime. I don't mean MIL or SIL alone I mean the whole ruddy lot of them (MIL, SIL, BIL plus partners and teenage kids). They stay a couple hrs, there's lots of shouting and laughing and playing etc but they wind up an already tired and ready for bed DC to a hyper state then bog off and leave us to deal with a wired child either bawling eyes out or screaming and unable to calm down for ages 
They know when bedtime is, they've been asked not to all pile in that time if it's just a random social call but take no notice. Short of not answering the door (which I would happily do after this evening but DH would never allow) I don't know how to get through to them thickheaded inconsiderate gits