Syntax explanation:

Interval: mention in terms of Years,months,weeks,hours,days
Number: Mention the number applicable to Interval

Date: to which date we have to add the Interval

Code:

Private Sub CommandButton1_Click()
Add 2 years to 2016
MsgBox DateAdd("yyyy", 2, "1-jan-2016")
Add 2 years to 2016
Range("A1").Value = DateAdd("yyyy", 2, "1-oct-2016")
deduct 2 years to 2016
Range("A2").Value = DateAdd("yyyy", -2, "1-oct-2016")
deduct 2 weeks to 2016
Range("A3").Value = DateAdd("ww", -2, "1-oct-2016")
Deduct 2 weekdays to 2016
Range("A4").Value = DateAdd("w", -2, "1-oct-2016")
Deduct 2 days to 2016
Range("A5").Value = DateAdd("d", -2, "1-oct-2016")
Add 45 months to 2016
Range("A6").Value = DateAdd("m", 45, "1-oct-2016")
Add 3 hours to 2016
Range("A7").Value = DateAdd("h", 3, "1-oct-2016")
End Sub

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DateAdd Function - Serial Dates

Code:

Private Sub CommandButton1_Click()
Dim i As Integer
'adding 100 days
For i = 1 To 100
Cells(i, 1).Value = DateAdd("d", i, "1-1-2016")
Next
End Sub