3weeks — Why 21 Consecutive Days?

The 21-Day Benchmark

3weeks fixes the goal period at 21 days. This number wasn't chosen arbitrarily.

The concept of "21-day repetition" is commonly cited in habit research. The theory holds that repeating a behavior daily for 21 days strengthens neural pathways enough that the action gradually becomes automatic. It's not an absolute proven law, but the 3-week unit is short and concrete enough to lower the psychological barrier to starting.

The Consecutive Check Structure

In 3weeks, you must check in every single day. Missing one day resets the count.

This is an intentional design decision. "I can do it tomorrow instead" is the beginning of not building a habit. The pressure to maintain the streak is precisely what motivates daily execution.

The Completion Experience

Finishing all 21 days triggers a celebration screen. It might seem like a long stretch, but people who've completed a 21-day run describe gaining a kind of confidence: "I can actually do this." Creating that experience is what 3weeks is built around.