Instrument 09 / decades
Lifetime Clock
Optionally enter a birth date and choose a framing horizon. One ring appears for each completed year, with a separate partial ring for the current year. Reset returns to a clearly labeled fictional example.
The fictional example uses a birth date 42 years and part of a year ago.
The horizon is a framing choice for the drawing, not a predicted death date or life-expectancy estimate. Dates remain only in this browser session and are not stored or sent anywhere.
What this does not measure
This clock does not predict lifespan, death, health, fertility, aging quality, or future years. It uses a birth date, today's device date, and a visitor-selected visual span.
Why this clock exists
The U.S. National Park Service explains that earlywood and latewood together usually form one annual tree ring, with ring width shaped by growing conditions. A human year has no comparable tissue boundary, so this cross-section is openly metaphorical. It trades a rapidly changing decimal age for completed rings and one partial outer arc, letting years accumulate as structure rather than as false precision.
National Park Service guide to dendrochronology