Why did the end-date of my monitoring period change?

BPCorrect sets the initial monitoring period as 7 days to encourage users to obtain at least 3 days of readings (2 AM and 2 PM readings one minute apart for 3 days, or 12 readings total) and optimally 7 days (28 readings total). However, if a user does not obtain at least 12 readings in the first 7 days, the monitoring period is automatically extended until at least 12 readings are obtained. When 12 readings are obtained, there is sufficient data to calculate an average blood pressure, and the monitoring period ends. If 12 readings are not obtained after 14 days, the monitoring period automatically ends and no average is calculated due to insufficient readings.