Hi, I don't know what Excel does, but maybe this could help:
B4X:
Dim mytime As Double = 0.837
Dim tsec As Double = 1/86400 'seconds on scale 0.0..1.0
Dim temp As Double = mytime / tsec 'mytime in seconds on scale
Dim mm1 As Int = temp /60 'mytime in minutes
Log(mm1)
Dim hr As Int = mm1 / 60 'hours
Log(hr)
Dim mm As Int = mm1 - (hr*60) 'minutes
Log(mm)
Here is another alternative pushing the DateUtils:
B4X:
Dim mytime As Double = 0.837
Dim m As Long = mytime*24*DateTime.TicksPerHour
Dim p As Period = DateUtils.PeriodBetween(0,m)
Log($"$2.0{p.Hours}:$2.0{p.Minutes}:$2.0{p.Seconds}"$) 'displays 20:05:16 You can get rid of seconds if you want