depends what the kids are doing in the morning.
ATM DS is getting up at 5.30am, which means my usual bedtime of 11pm-midnight isn't really cutting it for sleep requirements, so I retire a couple of hours earlier and read or do puzzles in bed and usually I feel tired earlier.
When they weren't stirring before 7 it's whenever I feel like it, or what ever time I finish my book lol, but I too am used to much broken sleep and night work.