The Duration form element allows you to select any two given dates within your form and will show the time difference between those two date/times.
To use it you'll need a form that has two date fields in it. When setting up the Duration form element, you'll just need to select which two date elements it will be looking at, and what time unit you'd like to see the duration in.
Note: If the Unit chosen is "Minutes", timestamps will be truncated at the second level and you will not be able to set a decimal places option. This means that timestamps for '10:59:01' and '10:59:59' would both be interpreted as '10:59'.
This duration field will be able to be treated as any other numeric field for the purposes of the Math and the Sum fields. To illustrate, here's an example of how this might be used:
If you've never used the form builder you can check out our other documentation that exists for customizing quality forms.