DateDiff malfunction

[vicks]

DateDiff does not return me correct date difference in years :

Dim dtDate1 AsDate
Dim DOB AsDate
DOB = #12/31/2000#
dtDate1 = #1/1/2005#

datediff(DateInterval.Year,dob,dtdate1) returns 5. It should return 4.
It must be using "Ceil" function internally.
What say?

 

[vis781]

Hi there,
I'm not too sure what your doing here. It should return 5 because it computes the time interval in years between 2000-2005, which is 5.

2000 -> 2001
2001 -> 2002
2002 -> 2003
2003 -> 2004
2004 -> 2005

Could you post back with exactly what your trying to accomplish here and we'll figure something out.

 

[vicks]

Date difference between 12/31/2000 and 1/1/2005 should be 4 years 1 day, right ?
12/31/2000 to 12/31/2004 = 4 Years
And 1/1/2005 = 1 Day

DateDiff() function doesn't look at the "date n month" part, it just looks at the "year" and calculates the difference...

 

[vis781]

Oh, sorry missed that. Well as far as i know because you have only specified the interval for a year, then that is all it will calculate.
As far as vb.net is concerned there is five years difference between the dates so that is what is being returned to you.

 

[jmcilhinney]

Moved to more appropriate forum.

 

[jmcilhinney]

I'd suggest not using DateDiff at all. Use the DateTime and TimeSpan structures and their members. Date2.Subtract(Date1) returns a TimeSpan object. You can then use its Years or TotalYears property, depending on exactly what you want.