Function DUR(deb As Date, fin As Date) As Date
Dim dat As Long, t As Date
t1 = TimeValue("8:0")
t2 = TimeValue("20:0")
jour = t2 - t1
dat = Int(CDec(deb))
t = TimeValue(deb)
DUR = PremDer(dat, t)
For dat = dat + 1 To Int(CDec(fin))
If Weekday(dat, 2) < 6 And IsError(Application.Match(dat, [Feries], 0)) Then DUR = DUR + jour
Next
t = TimeValue(fin)
DUR = DUR - PremDer(dat - 1, t)
End Function