By default, the Apple Watch is setup to sync Do Not Disturb status with your iPhone, meaning that when it’s enabled on either device — whether you do it manually or it kicks in on an automatic schedule — it’s enabled on both. While this can be handy if you find yourself toggling it on and off frequently, some users may prefer to maintain separate Do Not Disturb settings for each device, particularly when you consider that the Apple Watch doesn’t display notifications anyway once you’ve taken it off your wrist to go to bed.
Fortunately, it’s easy to unlink the two settings.
Just go into your Apple Watch app on your iPhone, select General, Do Not Disturb and turn the “Mirror iPhone” option OFF. Once you’ve done this, the Do Not Disturb setting will need to be enabled on each device individually, and the Apple Watch will never go into Do Not Disturb mode on any kind of a schedule, even if one has been set on the iPhone.
If you later decide you want to go back to keeping the settings mirrored, you can return to this same screen to re-enable the setting.