I have an A/B test run on my client site, but it has not achieved the significant number of visitors within the estimated time period for the test. Can anyone confirm if we could run the test for more number of days to achieve the significant/estimated number of sample size? If so, how many number of maximum days we could run the test further? And can we able to get the significant test results with running it for additional days than the initial estimation?
I presume you used the test-duration calculator to determine how long the test should be run, and you are wondering if statistically speaking if letting it run longer is going to compromise the statistical calculations. I think the "days" measure is the less important measure of duration. The more important ones from a stats perspective are total visitors and total conversions per experience. So in short, I'd say yes, run it until you reach the pre-determined per experience visitor volume you need to get a reliable reading on confidence level.