Putting 5.2.3, 5.2.4, and 5.2.5 together, suppose that the power calculations imply that you need to run an A/B test for a minimum of 5 days, if the experiment were run at 50%/50%. We would then recommend running it for a week to avoid day-of-week effects and to increase the power over the minimum. However, if the experiment were run at 95%/5%, the running time would have to be increased by a factor of 5 to 25 days, in which case we would recommend running it for four weeks. Such an experiment should not be run at 99%/1% because it would require over 125 days, a period we consider too long for reliable result; factors, such as cookie churn, that have secondary impact in experiments running for a few weeks may start contaminating the data