Kubernet’s Eternal Day and Eternal Night are desk clocks built around a rare complication: a secular perpetual calendar designed to account for the Gregorian century rule, not just ordinary leap years. The brand says each combines a re-engineered vintage mechanical movement with a calendar module whose date, day, month and moonphase change together within two seconds. Those are maker claims; the available sources do not independently verify the mechanism’s performance.
What “secular perpetual calendar” means
A standard perpetual calendar tracks the usual four-year leap-year cycle, but the Gregorian calendar has an exception: a year divisible by 100 is not a leap year unless it is also divisible by 400. That makes 2000 a leap year, but 2100, 2200 and 2300 common years; 2400 will be a leap year.
A secular perpetual calendar is designed to incorporate that century exception. Many conventional perpetual calendars need a correction at a century year such as 2100. Blue Lake Watches describes Kubernet’s mechanism as accounting for the exception, which is the core reason for the “secular” label. Blue Lake Watches’ Eternal Night listing
How Kubernet says the mechanism works
Kubernet says designer Chieh-Lin Ting re-engineered a vintage Shanghai Clock Factory movement and added an instantaneous-jumping secular perpetual calendar mechanism. The brand says it has applied three patents and that the date, day, month and moonphase transitions synchronize within two seconds. These are statements from Kubernet; the sources available here do not independently test the clock or verify the patent claims. Kubernet’s clock page
The Tool Desk
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- 【HD Display & Larg Font】The 𝗰𝗹𝗼𝗰𝗸 𝘄𝗶𝘁𝗵 𝗱𝗮𝘁𝗲 𝗮𝗻𝗱 𝘁𝗶𝗺𝗲 𝗳𝗼𝗿 𝗲𝗹𝗱𝗲𝗿𝗹𝘆 features a 7-inch 1024x600P HD LCD display that clearly displays the TIME, DATE, DAY of the WEEK, six time periods of the day[ MORNING, NOON, AFTERNOON, EVENING, NIGHT, MIDNIGHT, BEFORE DAWN ], and displays the ICONS of each time period in a bright Sun🌞 Moon🌙 visuals, ensuring that elderly individuals can easily understand the time & date.
- 【20 Normal Alarms & 20 Custom Reminders】Our 𝗱𝗲𝗺𝗲𝗻𝘁𝗶𝗮 𝗰𝗹𝗼𝗰𝗸𝘀 𝗳𝗼𝗿 𝘀𝗲𝗻𝗶𝗼𝗿𝘀 𝗲𝘅𝘁𝗿𝗮 𝗹𝗮𝗿𝗴𝗲 has Up to 20 normal alarms(every day, weekdays or weekends, specific dates) and 20 reminders for personal need such as taking medicine and drinking water. More uniquely, you can customize your special reminders for specific date and time, such as Birthday or Meetings Plan. When the alarm goes off, the clear colorful icon with specific words will also help your get rid of misunderstanding
- 【One-Touch Sleep Mode & 10-Level Brightness】Simply press the top button to activate sleep mode—the display turns off instantly for completely dark, undisturbed sleep. With 10 adjustable brightness levels ranging from 10% to 100%, you can easily customize the screen to suit day or night, reducing eye strain and promoting better rest by lowering brightness or turning it off completely at night.
- 【12 Themes and More Color Options】Compared with other alarm clocks with only black and white fonts, this 𝗱𝗶𝗴𝗶𝘁𝗮𝗹 𝗰𝗹𝗼𝗰𝗸 𝗹𝗮𝗿𝗴𝗲 𝗱𝗶𝘀𝗽𝗹𝗮𝘆 boasting 12 stunning display themes and different color options, you can customize different colors and themes according to your needs and different indoor scenes, each interface can meet the needs of different people such as students, vision impaired or elderly seniors with color blindness.
- 【Volume Control & 3/5/9 Minute Snooze】With 9 adjustable volume levels and 18 ringtones, you can set the alarm as loud as a rock concert or as soft as a whisper, it's a great choice whether you're a light or heavy sleeper. If you have trouble getting out of bed, the snooze function provides the perfect wake-up cushion. You can customize a 3, 5 or 9-minute nap time, and the alarm will go off again when the time is up.
The movement’s provenance is also attributed rather than independently documented. Kubernet and Blue Lake Watches trace its origin to 1979, while Fratello reports that the Shanghai Clock Factory movement had been used in travel alarm clocks and petroleum-extraction equipment. No archival movement record is cited in those accounts. Fratello’s July 31, 2025 launch article · Blue Lake Watches listing
Eternal Day and Eternal Night compared
| Variant | Appearance and details | Listed price and availability |
|---|---|---|
| Eternal Day | Fratello describes a bright silver-plated brass dial. Blue Lake’s listing identifies the bright version. Fratello · Blue Lake Watches | Blue Lake displayed CHF 6,000 and marked the listing sold out when indexed; the page gives no publication date, so this is not a current offer. Blue Lake Watches |
| Eternal Night | Fratello describes smoked translucent glass revealing the movement. Blue Lake specifies crystal with baked grey enamel and a leap-year indication. Fratello · Blue Lake Watches | Blue Lake displayed CHF 7,500 and marked the listing sold out when indexed; the page gives no publication date, so this is not a current offer. Blue Lake Watches |
The practical choice is primarily visual: a brighter, more legible dial treatment or a darker, more revealing view of the movement. The listed leap-year indication is specifically described for Eternal Night; the sources do not establish that the Day dial has the same display.
Rank #2
- Multifunctional: This product combines the functionality of a clock and a calendar, providing both time-keeping and date tracking in one compact device
- Clear Display: The large, easy-to-read display ensures you can quickly glance and see the current time and date with ease
- Convenient Design: With its sleek and modern aesthetic, this calendar clock can seamlessly blend into any home or office decor
- Easy Use: Simple controls allow for effortless setting and adjustment of the time and date as needed
- Versatile Placement: Whether placed on a desk, shelf, or mounted on a wall, this calendar clock offers versatile placement options to suit your needs
Published dimensions and movement specifications
Blue Lake Watches lists the following specifications. They are retailer-published figures, not independently measured results:
- Overall height: 135 mm; maximum base diameter: 154 mm.
- Movement: 15 jewels and 60 mm.
- Power reserve: eight days.
- Stated accuracy: no more than ±5 minutes over the eight-day reserve.
- Glass: low-iron glass with more than 91.5% light transmittance.
- Advertised limited-edition quantity: 99 pieces. This is the stated edition size, not confirmation of production totals or remaining stock.
Blue Lake Watches’ product specifications
Independent reader supportYour contribution helps us test, update, and keep practical guides available for everyone.Price, availability and recognition
Blue Lake Watches’ pages showed both versions as sold out when indexed. Because no date is shown on those product pages, their CHF prices should be treated only as historical listing snapshots. Fratello’s July 31, 2025 launch coverage also gave pre-order price equivalents in USD, EUR and GBP and reported expected December delivery; those launch-era figures and timing are not current purchase information. Check with the retailer or Kubernet for present stock, price, delivery timing, shipping and taxes before making a buying decision. Fratello, July 31, 2025 · Blue Lake Watches
Rank #3
- Day Of The Week, Calendar 2-In-1 Display: Simplify the complexity, high-color minimalist calendar, desktop calendar, large screen at a glance, simple and practical.
- Wood Grain, Metal Unique Shape: Smooth rounded edges, mechanical and wood grain metal with a sweep of the visual dullness, add a few points of vitality for your furniture.
- Mechanical Page Auto-Calibration: Set the current time, mechanical page auto-calibration. Simple and convenient operation, automatically recognize the day of the week according to the set time.
- One Key Backlight: Soft light does not touch the dark. Touch the back, one key backlight, easy to view in dark environment. Every late night it lights up the light of companionship for you.
- Suitable For Multiple Scenes And Multiple Home Decoration: The retro design is suitable for any room. Living room, dining room, bedroom, children's room, office, kitchen, etc.
Fratello reported that the clock was pre-selected for the 2025 GPHG Awards in the Clock category. The GPHG has an Eternal Night model page, but that record alone does not establish a final nomination or award win. Fratello · GPHG Eternal Night listing
Quick Recap
Best Value
- 𝗣𝗟𝗘𝗔𝗦𝗘 𝗡𝗢𝗧𝗘! Power adapter (included) is required as the power source of this product and 2 AA batteries (not included) only work for storing the clock settings in the case of power cut. It automatically resets to the correct time and date when the power returns.
- 【HD Display & Larg Font】This 𝗹𝗮𝗿𝗴𝗲 𝗱𝗶𝗴𝗶𝘁𝗮𝗹 𝗰𝗹𝗼𝗰𝗸 𝗳𝗼𝗿 𝘀𝗲𝗻𝗶𝗼𝗿𝘀 features a 7-inch 1024×600P high-definition LCD screen that clearly displays the TIME, DATE, DAY of the WEEK. It also divides the day into six distinct time periods:MORNING, NOON, AFTERNOON, EVENING, NIGHT, MIDNIGHT, BEFORE DAWN, each paired with bright sun🌞 and moon🌙 icons to visually represent the time of day, ensuring that elderly individuals can easily understand the time & date.
- 【20 Alarms & 20 Custom Reminders】Never miss an important task or event! This 𝗰𝗹𝗼𝗰𝗸 𝘄𝗶𝘁𝗵 𝗱𝗮𝘆 𝗮𝗻𝗱 𝗱𝗮𝘁𝗲 𝗳𝗼𝗿 𝗲𝗹𝗱𝗲𝗿𝗹𝘆 supports up to 20 standard alarms(every day, weekdays or weekends, specific dates) and 20 customizable reminders for personal needs such as taking medication, drinking water, waking up, or custom special reminders daily or specific date for your need. When the alarm is triggered, a clear colorful icon with specific words will also help your get rid of misunderstanding.
- 【One-Touch Sleep Mode & 10-Level Brightness】Simply press the top button to activate sleep mode—the display turns off instantly for completely dark, undisturbed sleep. With 10 adjustable brightness levels ranging from 10% to 100%, you can easily customize the screen to suit day or night, reducing eye strain and promoting better rest by lowering brightness or turning it off completely at night.
- 【12 Themes and More Color Options】Compared with other alarm clocks with only black and white fonts, this 𝗱𝗶𝗴𝗶𝘁𝗮𝗹 𝗰𝗹𝗼𝗰𝗸 𝗹𝗮𝗿𝗴𝗲 𝗱𝗶𝘀𝗽𝗹𝗮𝘆 boasting 12 display themes and different color options, you can customize different colors and themes according to your needs and different indoor scenes, which can meet the needs of different people such as students, vision impaired or elderly seniors with color blindness.
Rank #4
- Smart Digital Calendar & Wi-Fi Sync: This Wi-Fi connected smart calendar automatically synchronizes local weather, real-time temperature, and humidity. Stay updated with instant holiday reminders and precise timekeeping without manual settings.
- 7-Inch Eye-Care E-Paper Display: Featuring a premium 7-inch E-Ink screen, this desk calendar mimics real paper with zero blue light and no flicker for a comfortable reading experience. The 180° ultra-wide viewing angle ensures clarity from any corner of your office.
- Global Time Zone & Multi-City Clock: Designed for global professionals, it supports multi-time zone displays and pre-loaded global holiday data. A perfect electronic calendar for tracking international deadlines and festive events.
- Minimalist Desk Decor & Productivity Tool: The ultra-slim, sleek design fits perfectly as a modern desk accessory or bedside weather station. Its compact profile provides essential daily information at a glance to boost your productivity.
- Professional Executive Black Finish: The Classic Black matte finish offers a sophisticated, professional look, making it the ideal high-tech gift for corporate leaders, executives, and modern home offices.
Product prices and availability are accurate as of the date/time indicated and are subject to change. Any price and availability information displayed on Amazon at the time of purchase will apply.
