I want to be able to see at a glance when my watch is in DND mode. Is this something that a watchface developer could include on the watchface? Could it be something that is done by the OS on top of the watchface?
Oh cool, has this always existed? I’ve looked at a few watchfaces and none of them seem to have that as an available complication. Do you happen to know of one that does?
Yes, for the longest time. See GitHub - clach04/pebble_watchface_framework: Working, ready to build Bare-Bones watch face for Pebble (OG/Classic, Time, and Round) Aplite, Basalt, Diorite, and Chalk. With configuration and settings support. if you want to get started with it. All watches generated with thei framework have that built in. I just published (about 4 years later 
) the one I use a lot 7 timezones
forecaswatch2 is not based on my framework but has Quiet Time support built in - I can’t link here as I’m a new poster and limited to one URL in a post 