Since

Count the days since anything that matters — quit dates, milestones, streaks. On-device.

Counting elapsed days is the simplest possible measurement and it does something that a goal cannot: it rewards the present rather than a distant endpoint. That is why day counts are standard in recovery programmes and habit change — the number goes up for doing nothing wrong, which is a much easier win to collect.

The design risk is the same mechanism inverted. A long streak becomes something to protect, and a single break can feel like losing everything rather than one day. Counting several things at once helps, because it makes any one number less load-bearing.