Could someone please tell me why I cannot format SumAll as [h]:mm? It gives
an answer of :03, when it should be 1618.20.

I'd also like to know how to format as Text "-[h]:mm" because I have some
other calculations that will result in a negative number of hours/minutes.

Thank you!

Function SumAll(rng As Range)
Dim cell As Range
SumAll = 0

For Each cell In rng
SumAll = SumAll + cell.Value
Next cell
SumAll = Format(SumAll / 86400, "[h]:mm") 'convert seconds to
hours/minutes
End Function