Dim H5 As Date, H6 As Date, H7 As Date, H8 As Date
Dim s As Double, h$, m$
On Error Resume Next
H5 = CDate(TextBox5)
H6 = CDate(TextBox6)
H7 = CDate(TextBox7)
H8 = CDate(TextBox8)
s = H5 + H6 + H7 + H8
h = Format(s * 24, "0") 'heures
m = Format(s * 1440 - h * 60, "00") 'minutes
TextBox1 = h & ":" & m