Emits
Weather
ringing the hours
ambiance
Swap day and night descriptions for nocturnal creatures
PCs out when it’s not their daylight cycle have reduced vision.
Add scent and sound descriptions to room descs
Make it so the time doesn’t match RL time (offset time to allow players from various timezones to be able to experience day and night. Or have day and night change more frequently (i.e. one hour RL time is two hours game time.)
Food
Any PC can eat whatever they want. But to heal they need to eat X of their 'type' of food (Could also make it so they heal faster if they do, but don’t require it).