The three metrics

Every vein is measured in one of three ways. The metric you choose decides how you log progress and how the daily floor works. Pick the one that matches how the work actually feels.

Time

A time vein tracks minutes or hours. You carve it by logging how long you spent.

Use time when the value of the work is in showing up and staying with it, and the output is hard to count. Practicing an instrument, deep work on a project, meditation, studying. The floor is an amount of time, like 25 minutes.

Time veins pair well with a session timer: start it when you begin, stop it when you are done, and the minutes are logged for you.

Quantity

A quantity vein tracks a count. You carve it by logging how many.

Use quantity when there is a clear unit to count and the count is what matters. Words written, pages read, push-ups done, sales calls made. The floor is a number, like 500 words.

Quantity veins are the ones where a target and deadline shine: a total to reach by a date divides cleanly into a daily count. See The daily floor.

Daily

A daily vein is the simplest. There is no amount to measure. You either did it today or you did not. You carve it with a single tap.

Use daily for binary habits where doing it at all is the whole point. Taking medication, flossing, making the bed, a cold shower. The floor is just: done today.

Daily veins are quiet by design. There is no number to optimize, no graph to chase. They are there to make sure the small non-negotiables do not slip.

Choosing

A quick way to decide:

• Can you count the output in a natural unit? Use quantity.
• Is the value in time spent rather than output produced? Use time.
• Is it a yes-or-no habit where doing it once is enough? Use daily.

You can change a vein's metric later if you got it wrong, though it is worth a moment up front since the metric shapes how the floor and the cross-section behave.