How long must the canary run?

Total traffic is 2000 requests per second. A canary receives 5%. The metric of interest has mean $m$ and coefficient of variation $1.5$.

1. How long must the canary run to detect a 2% relative regression with 80% power at the 5% level?
2. How long to detect a 0.5% regression?
3. The team checks the dashboard every 10 minutes and ships when $p < 0.05$. Estimate their actual false-positive rate over a 24-hour window, and say what to do instead.