Excel VBA datediff to Calculate Months, Days and Month together? - excel

Question

I'm trying to calculate the time elapsed with the total amount of months, Days and Hours together using Datediff function. Is it not possible?
DateDiff("d hh", datein, Now)
What can I do?

Answer 1

That's not possible as the interval parameter can only be a single string.
You will have to do a bit more work like get the difference in hours and if it's above 24 convert the part before decimal separator into days
Sub Main()
Dim d1 As Date
d1 = "15/10/2014 08:00:03"
Dim d2 As Date
d2 = Now
Dim hrsDiff As Long
hrsDiff = DateDiff("h", d1, d2)
MsgBox IIf(hrsDiff >= 24, _
hrsDiff \ 24 & " days " & hrsDiff Mod 24 & " hours", _
hrsDiff & " hours")
End Sub

Answer 2

This is rough and ready, but is just directional. You could make a user defined function. This one returns 1:2:22:15 as a string (but you could return a custom class instance with variables for months, days, hours, minutes). It doesn't account for date2 being before date1 (not sure what happens then), nor does it account for date1 only being a partial day (assumes date1 is midnight).
Function MyDateDiff(date1 As Date, date2 As Date) As String
Dim intMonths As Integer
Dim datStartOfLastMonth As Date
Dim datStartOfLastHour As Date
Dim datEndOfMonth As Date
Dim intDays As Integer
Dim intHours As Integer
Dim intMinutes As Integer
Dim strResult As String
' Strip of any time
datStartOfLastMonth = DateSerial(Year(date2), Month(date2), Day(date2))
' check the dates arent in the same month
If Not ((Month(date1) = Month(date2) And Year(date1) = Year(date2))) Then
' how many months are there
intMonths = DateDiff("m", date1, date2)
Debug.Print (intMonths)
' how many days difference are there
intDays = DateDiff("d", DateAdd("m", intMonths, date1), date2)
Debug.Print (intDays)
' how many hours difference are there
intHours = DateDiff("h", datStartOfLastMonth, date2)
Debug.Print (intHours)
' how many minutes different are there
datStartOfLastHour = datStartOfLastMonth + (DatePart("h", date2) / 24)
intMinutes = DateDiff("n", datStartOfLastHour, date2)
Debug.Print (intMinutes)
Else
' Dates are in the same month
intMonths = 0
Debug.Print (intMonths)
' how many days difference are there
intDays = DateDiff("d", date1, date2)
Debug.Print (intDays)
' how many hours difference are there
intHours = DateDiff("h", datStartOfLastMonth, date2)
Debug.Print (intHours)
' how many minutes different are there
datStartOfLastHour = datStartOfLastMonth + (DatePart("h", date2) / 24)
intMinutes = DateDiff("n", datStartOfLastHour, date2)
Debug.Print (intMinutes)
End If
strResult = intMonths & ":" & intDays & ":" & intHours & ":" & intMinutes
MyDateDiff = strResult
End Function
Testing this:
?MyDateDiff("01-SEP-2014", "03-Oct-2014 22:15:33")
Gives:
1:2:22:15
i.e. 1 month, 2 days, 22 minutes and 15 seconds.
Reverse testing this by adding the components back onto date1 gives:
?DateAdd("n",15,DateAdd("h",22,DateAdd("d",2,DateAdd("m",1,"01-SEP-2014"))))
= "03-Oct-2014 22:15:33"
If we try with 2 dates in the same month:
?MyDateDiff("01-SEP-2014", "03-SEP-2014 22:15:33")
We get:
0:2:22:15
Reverse testing this:
?DateAdd("n",15,DateAdd("h",22,DateAdd("d",2,DateAdd("m",0,"01-SEP-2014"))))
Gives:
03/09/2014 22:15:00
But you may want to account for dates being the wrong way round...and you may only want date1 to be counted as a partial date if it starts later in the day....as I say, just a thought.
Regards
i

Answer 3

This may give you some ideas to correct for days in month or leap year Feb
Private Sub CommandButton1_Click()
DoDateA
End Sub
Sub DoDateA()
Dim D1 As Date, D2 As Date, DC As Date, DS As Date
Dim CA: CA = Array("", "yyyy", "m", "d", "h", "n", "s", "s")
Dim Va%(7), Da(7) As Date, Ci%
D1 = Now + Rnd() * 420 ' vary the * factors for range of dates
D2 = Now + Rnd() * 156
If D1 > D2 Then
[b4] = "Larger"
Else
[b4] = " smaller"
DS = D1
D1 = D2
D2 = DS
End If
[d4] = D1
[e4] = D2
DC = D2
For Ci = 1 To 6
Va(Ci) = DateDiff(CA(Ci), DC, D1)
DC = DateAdd(CA(Ci), Va(Ci), DC)
Va(Ci + 1) = DateDiff(CA(Ci + 1), DC, D1)
If Va(Ci + 1) < 0 Then ' added too much
Va(Ci) = Va(Ci) - 1
DC = DateAdd(CA(Ci), -1, DC)
Cells(9, Ci + 3) = Va(Ci + 1)
Cells(8, Ci + 3) = Format(DC, "yyyy:mm:dd hh:mm:ss")
End If
Da(Ci) = DC
Cells(5, Ci + 3) = CA(Ci)
Cells(6, Ci + 3) = Va(Ci)
Cells(7, Ci + 3) = Format(Da(Ci), "yyyy:mm:dd hh:mm:ss")
Cells(10, Ci + 3) = DateDiff(CA(Ci), D2, D1)
Next Ci
End Sub