Hi Alex,
@Alexb91 wrote:
But the numeric indicator doesn't return a time but a numeric value.
A "time difference" is a number: it's the (fractional) number of seconds between two timestamps.
Did you know you can change the display format for numeric indicators? (Basic LabVIEW knowledge…)
They even allow to show time values in their format properties dialog. As you don't want to show an absolute timestamp I recommend to try the relative time format!
Example: