UPDATE:
I initially had an IFTTT recipe for all bulbs to dim by 5% each half hour starting around 8pm in the summer, 7pm in the winter, but realized that would no longer work when my daughters' rooms kept lighting up each half hour. My living room has 7 Hue White+Color in can lights. One or All isn't that useful when you expand to multiple rooms, or very distinct fixtures. I still have an IFTTT recipe that turns off all lights in the house at 1am, as a failsafe in case I forget to turn anything off.
I've since added 3 Hue White (the advanced gen 2) to my infant daughter's room, and 2 Hue White + Color to my older daughter's room, each with a Hue dimmer switch remote. I made the switch away from IFTTT recipes to native HomeKit time-based triggers because it's much easier to setup scenes and have the trigger activate the scene than it is to create 7 IFTTT recipes (1 for each bulb) for the living room, 3 IFTTT recipes (1 for each bulb) in the nursery, and two IFTTT recipes (1 for each bulb) in my daughter's room. The main downside is that since I don't have an Apple TV, the dimming doesn't work unless I am at home - this is an issue when I'm not at home but my family is, and if we're on vacation the house no longer gives the impression that we're still at home.