Microsoft KB Archive/210522

= ACC2000: Two Functions to Calculate Age in Months and Years =

Article ID: 210522

Article Last Modified on 6/24/2004

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APPLIES TO


 * Microsoft Access 2000 Standard Edition

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This article was previously published under Q210522



Advanced: Requires expert coding, interoperability, and multiuser skills.

This article applies to a Microsoft Access database (.mdb) and to a Microsoft Access project (.adp).

For a Microsoft Access 2002 version of this article, see 290190.



SUMMARY
This article shows you how to create two functions to calculate the age of a person or thing based on a specified date.

NOTE: You can see a demonstration of the technique that is used in this article in the sample file Qrysmp00.exe. For information about how to obtain this sample file, please see the following article in the Microsoft Knowledge Base:

207626 ACC2000: Access 2000 Sample Queries Available in Download Center



Creating the Functions
Type the following code in a module: '========================================================== ' General Declaration '========================================================== Option Explicit

'************************************************************* ' FUNCTION NAME: Age ' ' PURPOSE: '   Calculates age in years from a specified date to today's date. ' ' INPUT PARAMETERS: '   StartDate: The beginning date (for example, a birth date). ' ' RETURN '   Age in years. ' '************************************************************* Function Age (varBirthDate As Variant) As Integer Dim varAge As Variant

If IsNull(varBirthdate) then Age = 0: Exit Function

varAge = DateDiff("yyyy", varBirthDate, Now) If Date < DateSerial(Year(Now), Month(varBirthDate), _                       Day(varBirthDate)) Then varAge = varAge - 1 End If  Age = CInt(varAge) End Function

'************************************************************* ' FUNCTION NAME: AgeMonths ' ' PURPOSE: ' Compliments the Age function by calculating the number of months ' that have expired since the last month supplied by the specified date. ' If the specified date is a birthday, the function returns the number of '    months since the last birthday. ' ' INPUT PARAMETERS: '   StartDate: The beginning date (for example, a birthday). ' ' RETURN '   Months since the last birthday. '************************************************************* Function AgeMonths(ByVal StartDate As String) As Integer

Dim tAge As Double tAge = (DateDiff("m", StartDate, Now)) If (DatePart("d", StartDate) > DatePart("d", Now)) Then tAge = tAge - 1 End If  If tAge < 0 Then tAge = tAge + 1 End If

AgeMonths = CInt(tAge Mod 12)

End Function

Testing the Age and AgeMonths Functions
To test the Age and AgeMonths functions, follow these steps.

IMPORTANT: The following steps ask you to change the date on your computer. Make sure that you complete step 6 to reset the date to the current date.  By using the Date/Time tool in Control Panel, make a note of the current date, and then set the date to June 3, 2000. Open a module or create a new one. On the View menu, click Immediate Window.  Assume your friend's birth date was November 15, 1967 and today is June 3, 2000. Type the following line in the Immediate window, and then press ENTER: ?Age("11/15/67") Note that Microsoft Access responds with the value 32 (years).   Type the following line, and then press ENTER: ?AgeMonths("11/15/67") Note that Microsoft Access responds with the value 6, indicating that six months have passed since this person's last birthday. Your friend is 32 years and six months old.  By using the Date/Time tool in Control Panel, reset the date to the current date that you noted in step 1.</li></ol>

Using the Age and AgeMonths Functions
The following procedure explains how to mark old orders by placing the age value in a new control. <ol> In the sample database Northwind.mdb, type the Age and AgeMonth functions in a new module.</li> Open the Orders form in Design view and add an unbound text box control.</li> Type the following line in the ControlSource property of the new text box control:

=Age([OrderDate]) & " yrs " & AgeMonths([OrderDate]) & " mos"

</li> View the form in Form view. Note that the age of the order is displayed in the new text box control.</li></ol>

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