Concrete vs abstract numbers
Behavioral research keeps finding that concrete, countable representations drive action better than abstract ones: "save $4/day" beats "save $1,460/year"; "11,700 days lived" feels like a possession while "32 years" feels like a category. The day-count formats work because the brain can hold them.
The counter practices
Sobriety chips count days (not months) deliberately; language-learning streaks count days; the 10,000-day birthday tradition celebrates the countable. All exploit the same mechanism: a number that increments daily is a companion, while a number that increments annually is a filing event.
Building your own
Pick a start date that matters, compute the days (this site exists for exactly this), and put the counter where you see it. The practice costs nothing and does one thing well: it converts time from something that happens to you into something you are counting — which is a different way to live inside it.