John Armitage’s Perpetual Calendar: A Clock That Remembers February

On a dull Tuesday in Somerset, I met a man who had found a solution to a small but persistent worry I had not known I was carrying.

You know the feeling: it is late February, the calendar seems ready to drop away beneath you, and people start asking, “Is it 28 or 29 this year?” Naturally, our phones know the answer, but a mechanical clock on the mantelpiece can be less forgiving. It keeps ticking loyally through birthdays and bills, only to falter on 30 April like a mule digging in its heels. In a snug workshop, carrying a faint scent of tea and metal filings, a clockmaker showed me his answer in brass and steel: a timepiece that quietly recalls what most of us overlook. He has made a clock that recognises leap years and adjusts itself overnight, without alarm, tinkering or the realisation that it is a day behind. The remarkable thing is that it has not been programmed. It has been taught how to remember.

The man teaching machines to remember February

John Armitage is a quietly spoken clockmaker, with ash-dark eyelashes and an instinctive modesty about his work. His workshop sits behind a florist, hidden off a market street where buses exhale and teenagers hurry past in rain-soaked trainers. It is warm inside, with workbenches in gentle disorder: lathes, tweezers, oilers and ageing jam jars packed with screws. A kettle snaps off, while a narrow ribbon of steam joins the scent of brass dust. John moves a clock case towards me in both hands, as carefully as if he were holding a baby.

Raised in Sheffield, he still has an even northern rhythm to his voice. A small scar remains on his index finger, left by a mainspring that sprang free and caught him. “Best lesson I ever paid for,” he says with a joke. Most of us have experienced the embarrassment of a clock or watch letting us down; for John, it happened when a customer telephoned to report that their date display was wrong on 1 March. That was the day he resolved to create something that would not require an apology.

The quiet drama beneath the dial

When he lifts the rear of the case, the room appears to fall silent. The familiar ensemble is there: the escape wheel flicking, the balance wheel drawing breath, and the lever marking time like a metronome in a school hall. Underneath the components that keep time, another world turns slowly, like a city beneath a city. There are rings and cams, minute fingers tipped with sapphire, and springs curved like smiles. Their purpose is not to display the time; it is to make the months behave properly.

John refers to this arrangement as the calendar train. Its 31-tooth date ring holds the numbers, assigning one tooth to every day. At midnight, a lever gives it a gentle push forwards, a movement you can almost sense in your throat when the room is quiet. Without intervention, it would proceed from 1 to 31 in every month, unaware that people have inconveniently devised months ending on 30 or 28. The solution lies in a collection of memory components that determine when days must be omitted.

The 48-month memory wheel

Beneath the date ring is a wheel that completes one turn every four years. Its 48 months are represented not with numerals but with varying depths. Each month forms a step around the rim: a deep cut for February, a slightly shallower one for 30-day months, and full height for those with 31 days. A steel feeler sits against the rim, interpreting its profile like a fingertip travelling along the spine of a book. Detecting a shorter month allows it to make the lever advance the date ring two or three times rather than once, clearing the unnecessary dates in a single midnight movement.

February needs its own arrangement. In ordinary years, the feeler falls to the lowest point of the step and the mechanism instructs the date display to move directly from 28 to 1. Every fourth February, however, the wheel offers a marginally raised step, just high enough to permit the 29th. The distinction is only the width of a breath: one overly assured pass with a file could destroy it. John holds up two components that look almost identical, and I cannot distinguish one from the other. He gives the quiet smile familiar from craftspeople when their visitor has not yet spotted the magic.

There is also the inconvenient reality of the Gregorian calendar: years divisible by 100 are not leap years unless they are also divisible by 400. Many clockmakers simply accept that the owner will have to correct the date manually in 2100. John felt that a shrug was inadequate. He added a slowly travelling “century cam”, reduced through gearing so extreme that it takes 400 years to complete one revolution. A single additional notch removes 29 February once every century, then restores it every fourth century. It is an eccentric miniature moon, moving slowly enough to challenge the mind, yet progressing steadily towards a date neither of us will see.

From brass to inevitability

His work began on graph paper. He sketched wheels in pencil, redrew them, then woke at 3 a.m. to alter a tooth count on a Post-it note. His dog, Molly, became familiar with the evening sound of the mainspring winder. Yellow brass curls gathered on the workshop floor like scattered confetti. He would raise the 48-month wheel to the light as though examining a coin, using a loupe to ensure each step had been cut to the correct depth.

The tolerances involved are more human than digital. A feeler pressing too firmly introduces friction and erodes the cam; one touching too lightly may fail to produce the necessary skip every time. John shows me a spring that he produced thirteen times before finding a strength that was just short of fussy. He breathes onto a jewel until it mists over, then polishes it with a soft leather square as though soothing a nervous horse. The mechanism is not so much fragile as it is exacting, relying on patience.

The perpetual calendar’s midnight choreography

Ten minutes before midnight, the carriage begins to rise. John’s description is that the lever collects energy from the hour wheel in the manner of a bow being drawn. The date wheel is held securely by a jumper spring, ready for its movement. At midnight, the locking finger retreats and everything shifts: a clean click that can be heard, followed by another that can be felt as the clock case tightens in your hand. During shorter months, it clicks twice and on occasion three times, an unseen drumroll taking place behind the dial.

He has included safeguards to prevent damage when the time is adjusted close to midnight. For a narrow part of the day, the quickset function is locked, ensuring that the mechanism cannot be forced while it is operating. He indicates a brass beak designed to stop two fingers from attempting to move the date simultaneously: a peacekeeper. Anyone who has felt the crunch beneath their thumb when an inexpensive watch resists a date adjustment will know the noise his engineering has removed. Midnight ought to be a waltz rather than a wrestling match.

Why this sort of accuracy appeals

All of that effort for one day every four years, you might ask. Perhaps its appeal is the understated reassurance of knowing that something is taking care of matters as you sleep. We are surrounded by devices that beep, prod and demand attention, whereas mechanical memory feels more considerate. It offers reassurance without a sound. In truth, none of us performs this task every day.

We place faith in our phones, yet a phone has no soul and will not remain on a mantelpiece after you are gone. A clock that honours February can feel as though somebody remembered to leave a lamp lit. It promises that the awkwardness of a month will not put your life out of step. A good clock is a promise kept. When John says that his calendar will remain correct until the year 2400, the silence that follows is part mathematics and part myth.

The day the leap did not land

John recounts an episode from 2015, the year before the following leap year. His first version was nearly ready: a compact table clock in a walnut case with the faint fragrance of old books. He began running it in September, letting it hum on the bench while winding it each day and recording observations in a pencil log. On 29 February 2016, it leapt like a gymnast and stuck the landing.

However, later that November, during the change from the 30th to the 1st, it advanced by only one tooth where it should have moved by two. It was a rare and minor failure, but still a failure. He tracked the cause to imperceptible wear in the jumper spring, the kind of issue that would mean little if humans had not designed months as though they were trick questions. He replaced the spring steel, polished the cam edge and redesigned the feeler so that it rolled instead of slid. During the next cycle, the click was sharp enough to sound confident.

What is required to encode a century

The 400-year cam is a form of romantic madness. John shows me the gear train responsible for it, each stage reducing the speed like whispers travelling down a church pew. The final arbor moves so gradually that he drew a faint black-ink mark on it in order to observe any change over several weeks. It contains a notch that makes the calendar reject 29 February in 2100, 2200 and 2300, before permitting it once more in 2400. For a sense of scale, imagine watching a wheel spend a month moving by a millimetre.

He is not blind to the boldness of the idea. “Someone will service it,” he says, “and someone else will swear at my choices.” He makes notes and conceals them beneath the base plate, directing future repairers on where to apply oil and what should be left untouched. Every clock also comes with a hand-drawn chart, a small folded guide to future years. The clock does not need it, but owners appear to enjoy checking the machine’s memory against their own. Leap years are not mistakes; they’re the Earth’s confession that life is messy.

Hands and hearts

I ask who would choose to buy such a clock. John says it is not only collectors. One was a midwife in Leeds, who wanted a clock to reflect the unusual, elastic hours of night shifts. Another was a retired maths teacher, keen to demonstrate to grandchildren that machines can retain rules more effectively than people. There was also a couple married on 29 February who wanted their anniversary to feel acknowledged. Those stories make the workshop seem warmer.

We have all known the feeling when a small mechanical kindness resolves a more significant frustration: a door latch closing with a satisfying snick, or a tap ceasing to drip after a washer is replaced. A clock that does not require your hand on its crown on 1 March offers the same grace. Somewhere, someone has cared enough to save you a minor annoyance. It may only be one day, yet it is also an assurance that your days will proceed in a gently ordered way.

Why bother when a chip could do it?

John laughs at the question. He owns quartz clocks and, like everyone else, carries a phone. He does not claim that his work is necessary in the way a kettle or fuse box is necessary. It belongs to another category: useful as a window or music. Life is possible without it, but it makes life easier to love.

There is also a quiet desire to master a rule without relying on electricity: to form brass and steel into a machine that understands February’s secret simply through touch. He says that he once explained the 48-month cam to a group of twelve-year-olds using biscuit tins and cardboard. They understood immediately. You could see the realisation arrive: memory could be encoded in shape rather than software. Memory pressed into metal remains memory.

Listening for the leap

On my final visit, John set the clock to the evening of 28 February in a leap year. We sat with mugs of tea, waiting as though at a railway station. The workshop grew quieter while the town outside continued with its usual sounds. A bus sighed somewhere, and a gull protested. Indoors, the second hand travelled neatly onwards; then midnight came, followed by one click and a second, and 29 appeared in the small window with such precision that I nearly believed it was magic.

John looked satisfied, though not surprised. It is his preferred party trick, although he would never use that term. The clock had simply done what it always does: recalled a rule that we often forget and followed it without complaint. This is a perpetual calendar in a small British workshop. Its romance lies not in the leap itself, but in the certainty.

The small future on your mantel

As I left, rain threaded across the street while the florist swept petals into a dustpan. I continued to think about the century cam, plodding towards a day long after our names have vanished from the speech of the living. Designing for a horizon so distant is audacious, perhaps even cheeky. Yet it also carries humility. You create something that performs properly as far as your sight reaches, then place your trust in it beyond the bend.

John’s clocks will not announce headlines. They will not request updates or dim themselves to conserve energy. Instead, they will rest on a shelf and tick; then, at midnight on the final day of the appropriate months, they will make their discreet secret skip and keep your arrangements in order. They will remove one small future irritation. Stand close enough and listen, and you may hear it: a machine that learned to remember February once, and never forgot.