Ask someone to draw time and watch what happens.
Some people draw a horizontal line, left to right. Birth on the left, death on the right, everything else in between. The past is behind them. The future is ahead. Time has a direction and it does not loop back.
Other people draw a circle. January at the top, summer on the right, autumn at the bottom, spring on the left. When December ends you return to the beginning. The year has no end point, only a rhythm.
A third group draws something harder to name. A spiral, maybe. Or a helix. Time moves forward but it also orbits. You pass through the same seasons, the same months, the same weekly rhythms, but each pass is slightly different from the last. You are not where you were a year ago, even though the calendar says the same date.
Cognitive scientists have spent decades studying these mental images. The research is clear on one point: humans cannot think about time without converting it into space. Time has no shape, no colour, no position. But the brain insists on giving it all three.
Time Needs a Body
In 2007, psychologist Daniel Casasanto and linguist Lera Boroditsky published a study at Stanford showing that people cannot process duration without recruiting spatial representations. Participants who saw a longer line on screen judged a simultaneous tone as lasting longer, even when it did not. But the reverse was not true - hearing a longer tone did not make people see a longer line.
The finding was stark. Space shapes our perception of time, but time does not shape our perception of space. The relationship runs in one direction. We borrow from the concrete to understand the abstract, and never the other way around.
This asymmetry shows up everywhere in language. We talk about a long weekend and a short meeting. We look forward to Friday and look back on childhood. We say time flies and deadlines approach. Every temporal metaphor is secretly spatial. We have no other vocabulary for it.
But the shape we give time varies. And that variation is the interesting part.
The Line
Western cultures overwhelmingly default to the linear mental timeline. Past on the left, future on the right, matching the direction of reading. Arabic and Hebrew speakers tend to reverse it - past on the right, future on the left. Mandarin speakers sometimes orient time vertically, with the past above and the future below, reflecting the traditional top-to-bottom writing direction.
The linear model treats time as a one-way street. Each moment is unique. Each day is consumed and cannot be revisited. History has a beginning, a middle, and an end. Christianity, Islam, and Judaism all structure time this way - creation, life, judgment. There is a destination.
In a developer's career, the linear view is the resume. Started as a junior in 2015. Became a senior in 2019. Moved to a lead role in 2022. Each year is a rung on a ladder that only goes up. The line does not curve and it does not repeat.
The Chronicle layout in Codex Stellarum is the linear shape made visible. Year by year, band by band, the stars unfold like geological strata. The earliest years are at the top. The most recent are at the bottom. You read it like a timeline, like a core sample drilled through sediment. Each layer is distinct. The whole thing has a direction.
People who choose Chronicle tend to be drawn to narrative. They want to see the story unfold. Where did I start? How did it change? What happened next?
The Circle
In 2019, researchers at the University of Oslo and the Norwegian Broadcasting Corporation ran a large online survey with 76,922 participants. They asked people to place the months of December and March on a circle. The majority placed December near the 12 o'clock position and March near 3 o'clock - the same positions as on a clock face.
But about a third of respondents preferred other shapes entirely. Ellipses, rectangles, spirals, and arrangements so idiosyncratic they were tied to specific landscapes or personal memories. The researchers concluded that while the circle is the most common spatial model for a year, there is genuine variation in how individuals map time.
The circular model is ancient. It comes from observation. The sun rises and sets. The moon waxes and wanes. The seasons return. Crops are planted and harvested in cycles. For most of human history, time was circular because the evidence of the senses said so. The rising and setting of stars is isomorphic with the circle - the same constellations return to the same positions at the same time each year.
In a developer's life, the circular view captures rhythm. The quarterly sprint cycle. The annual review. The conference season. The December freeze. The January burst of motivation. These patterns repeat, year after year, and recognising them is a form of self-knowledge.
The Planisphere layout is the circular shape. Months orbit the circumference like hours on a clock face. January sits at the top and the year wraps around. Multiple years can overlay, creating concentric rings of activity. You can see at a glance which months are consistently bright and which are consistently dark, year after year.
People who choose Planisphere tend to be drawn to pattern recognition. They want to see rhythm. When am I most productive? Is there a seasonal shape to my work? Do I always slow down in August?
The Spiral
Neither the line nor the circle fully captures how most people experience time. The line implies that each moment is unique and unrepeatable. The circle implies that time returns to the same place. Both are partly right and partly wrong.
A spiral resolves the tension. It moves forward - you are always progressing, always aging, always accumulating experience. But it also orbits - you pass through the same months, the same seasons, the same rhythms. Each pass is different because you are different. March 2026 is not March 2024, even though the calendar is identical, because you have changed in the intervening loops.
The philosopher Friedrich Nietzsche wrote about eternal recurrence - the idea that you might live your life over and over, infinitely. He meant it as a thought experiment about how to live. Would you choose the same life again? The spiral is a gentler version of this idea. You do not repeat your life. But you revisit its rhythms, and each revisitation carries the weight of every previous pass.
In cognitive science, the spiral shows up as a natural hybrid. People who report "spatial sequence synesthesia" - a condition where time sequences have vivid spatial locations in the mind's eye - sometimes describe their year as a spiral rather than a line or circle. The shape captures both progression and periodicity in a single form.
In a developer's career, the spiral is the most honest shape. You are not the same programmer you were three years ago, but you are still working through the same patterns - bursts of energy, periods of rest, seasonal rhythms, annual cycles. The code changes. The language changes. The problems change. The rhythm does not.
The Helix layout is the spiral made visible. Time unwinds from the center outward. The earliest contributions sit at the core and the most recent trace the outer edge. The shape is organic and continuous - there are no hard boundaries between years, just a flowing curve that tightens and loosens with activity.
People who choose Helix tend to be drawn to feel. They are less interested in reading the data and more interested in experiencing it. The Helix is the most visually striking layout because the spiral creates natural tension - the eye follows the curve inward and then back out, tracing the developer's journey as a single, unbroken path.
Why Shape Matters
The shape you give your data changes what you see in it.
A linear chart of the same GitHub contributions shows growth or decline. A bar that goes up or a bar that goes down. The question it answers is: am I doing more or less?
A circular chart shows rhythm. Bright spots and dark spots repeat at the same positions each year. The question it answers is: when do I work?
A spiral shows both. Movement and recurrence. Change and continuity. The question it answers is harder to articulate, which is why it tends to be the layout that makes people pause longest when they see it for the first time.
Cognitive scientists call this "framing." The same information, presented in different spatial configurations, activates different interpretive frameworks in the brain. A temperature reading presented as a number feels like a fact. Presented as a rising line on a graph, it feels like a trend. Presented as a colour on a heat map, it feels like an environment. The data has not changed. The frame has.
Codex Stellarum's three layouts offer three frames for the same data. The Chronicle says: here is your story, from beginning to now. The Planisphere says: here is your rhythm, repeating across the years. The Helix says: here is your journey, spiralling outward from where you started.
Each one is true. Each one is incomplete. The shape you prefer says something about how you think about your own time.
Discover which shape fits your story. Enter your GitHub username at codexstellarum.com and try all three layouts - free to preview, prints from £25.