The Apple Watch is a valuable timepiece that is meant to look good with whatever you're wearing (which is why there's a healthy ecosystem of watch bands), while at the same time it can be a fitness companion that tracks how and where you burn calories, from the gym to underwater. Sometimes these two worlds don't overlap well.

So instead, dedicate the old watch as your workout watch – who cares if it gets scuffed, scratched, dented, sweaty or gross? (Just make sure you clean it properly at some point.)

In the Apple Watch app on the iPhone, tap My Watch at the bottom of the screen, then tap All Watches. Tap the Add Watch button and follow the instructions for pairing the watch.

When you take off your everyday watch and put on the old watch, all your daily exercise progress and notification settings transfer to it automatically.

It's natural to want to check the time if you wake up in the middle of the night, but do you want a bedside clock that lights up the entire room with its giant LED numbers? (Maybe it was the clock that woke you up!)

Nightstand Mode on the Apple Watch displays the time, date, battery level and the next alarm when the watch is connected to its charger and sitting on its side. The screen remains off until you tap the screen or press one of the physical buttons, then turns off after a few seconds.

To enable the feature, open the Apple Watch app on your iPhone, tap General and then turn on Nightstand Mode. Or, on the watch itself, open the Settings app, go to General > Nightstand Mode and activate the Nightstand Mode switch.

While sleep tracking can be helpful, another reason to wear an Apple Watch at night is to use it as a silent alarm clock in the morning. Use the Sleep app to set an alarm, but keep the watch in Silent mode. You'll wake to a thrumming series of taps on your wrist, which won't disturb a partner the way a loud, conventional blaring alarm would.

One of the Apple Watch's health features is sleep tracking, not only counting the hours you spend asleep but also gathering data about the quality of those restful hours. Anecdotal experience suggests that sleep tracking can help with self care, and scientific study also points to sleep as a necessary part of good heart and movement health.

That is, if your watch's battery lasts all night, which means you need to charge it sometime during the day.

Instead of plotting out daily charging times, use an old Apple Watch as your nighttime watch while your everyday watch charges. Set it up as a second watch as described above in "Make it a dedicated exercise Apple Watch" and then swap watches at bedtime. The Health data syncs to your iPhone from either device. (And then your regular watch can act as your bedside clock using Nightstand Mode.)

Following the long tradition of handing down yesterday's technology, an older Apple Watch can be a great accessory for a child or other family member. If you want to keep it managed within your Family Sharing group (i.e., the people included under the umbrella of your Apple ID), you can use Family Setup to configure it for one of them.

Make sure the watch has been unpaired and erased, hold the watch near your phone, and tap Set Up for a Family Member. Follow the setup steps, choosing the person from your Family Sharing group who will use the watch.

For children, you can enable Schooltime, a mode that limits features during hours you specify.

An Apple Watch Series 4 model or later is required, as is an iPhone 6s or later with iOS 14 or later for setup, and not all features are available when the Apple Watch is set up as a family watch.

Setting up an old Apple Watch for an elderly member in your Family Sharing group can give you peace of mind and aid them in possible emergencies. Even if they don't use any features other than the clock, fall detection can alert first responders and you (if you're listed as a contact in the Emergency SOS settings) if they take a serious stumble.

The watch also samples heart-rate data to measure Heart Rate Variability (HRV) and to notify the wearer when their heart rate drops or spikes without an obvious cause such as exertion. Unfortunately, some other health features are not available on Family Sharing watches, such as ECG, Medications and Walking Steadiness.

Instead, you could set up the watch with their own iPhone, not as a Family Sharing device, which lets them use all of the features supported by the model you're passing along.