It would be great to have the option to adjust the testing timeframe once an A/B test has gotten underway. There could be utility in the ability to shorten or lengthen the time. Thank you for considering!
Status: Idea Submitted
This idea is submitted here too: https://community.hubspot.com/t5/HubSpot-Ideas/The-ability-to-change-the-A-B-test-duration-after-the-email-is/idc-p/880943#M160924