I'm trying to display a time interval, e.g., 3.2 hours, in HH:MM format. So 3.2 converts to 3:12.
I was successfully able to do this using:
ToTime(Integer(Format([Departure Date: Sum: Flight Time Est]*3600000,'#')), 'hours,minutes,seconds', '%d:%02d')
But then I get this error which warns me that HH:MM may not add up correctly

And indeed it does not add up correctly!
Is there a way to get the HH:MM format where it DOES add up correctly, or is this not a functionality that is available at this time?