It's possible to select 1- to 5-day measurements in Firstbeat Life app. The first measurement must be at least three days. After the first measurement, you can choose the length of the measurement as you like.
Before starting a measurement, you have to select how many days to measure: one, two, three, four or five days. Below your selection you can see how many electrodes you need for the measurement on average.
Check also the guidance for starting the measurement.
Once the measurement days are full you will see that the progress is 100 %. The app then gives you an option to continue measuring, or sync the data. Don't measure more than five (5) days.
Check also the guidance for creating the report.
If there are problems with starting the measurement, check here what to do: What to do if starting a new measurement fails
If you need any further help with this, don't hesitate to contact Firstbeat Support.