The oldest surviving clock in England is that at Salisbury Cathedral, which dates from 1386. A clock erected at Rouen, France, in 1389 is still extant, and one built for Wells Cathedral in England is preserved in the Science Museum in London. The Salisbury clock strikes the hours, and those of Rouen and Wells also have mechanisms for chiming at the quarter hour. These clocks are large, iron-framed structures driven by falling weights attached to a cord wrapped around a drum and regulated by a mechanism known as a verge (or crown wheel) escapement. Their errors probably were as large as a half hour per day. The first domestic clocks were smaller wall-mounted versions of these large public clocks. They appeared late in the 14th century, and few examples have survived; most of them, extremely austere in design, had no cases or means of protection from dust.
You don't have to use all of those features, however. You can set them in a variety of combinations, or even turn all of them off except for the flashing red lights. You can also set the length of the alarm's ring from one to 60 minutes, and choose a snooze option from one to 30 minutes. Plus, the clock has dual alarms, so both you and your partner can have different wake-up times.
“I bought this light because my partner and I need to be up early for work, but our bedroom has very poor natural light. Within a week, I’ve already noticed a difference in my energy levels and mood. The sunrise simulation works perfectly; by the time the ‘alarm’ (peaceful bird noises) goes off, I’m already feeling naturally awake — not groggy or jolted out of my sleep. I feel much more rested, and my average resting heart rate reflects that. I also really love the sunset feature. I wasn’t expecting to get much use out of it, but I feel like it does a great job of helping me settle into bed at the end of the day.”