How do I find difference in MONTH for two DataTime

[Ali Baba]

Hi,

Is there is equivalent of VB's DateDiff() method in C#. I need to find
difference in months between two dates that are years apart. Docs says
that I can use TimeSpan like:

TimeSpam ts = date1 - date2;

but this gives me data in Days. I don't want to divide this number by 30
because not every month is 30 days and since the two operand values are
quite apart from each other, I am afraid dividing by 30 might give me a
wrong value.

Any suggestions???

 

[Nicholas Paldino [.NET/C# MVP]]

Ali,

You can call the DateDiff function in VB. Add a reference to
Microsoft.VisualBasic.dll. Once you do that, you can call the static
DateDiff method on the DateAndTime class in the Microsoft.VisualBasic
namespace.

Hope this helps.

 

[Jerry Negrelli]

The VisualBasic.dll's date functions may be suited for
doing what you require relatively quickly, but its
probably just as easy to write your own. I haven't
tested this, but I have a feeling all you need is
something like this:

int monthsApart = 12*(date2.Year-date1.Year) +
date2.Month-date1.Month;

01/01/00 - 01/01/03 = 36 months apart
12/01/00 - 01/01/03 = 25 months apart
01/01/00 - 06/01/99 = -7 months apart


Jerry Negrelli
Senior Software Engineer
Data Scientific Corporation

 

[Ali Baba]

Nicholas,

This is a good idea. However, what affect is this going to have on my
deployment?

 

[Nicholas Paldino [.NET/C# MVP]]

Ali,

None, Microsoft.VisualBasic.dll is distributed with the .NET framework.

 

[Petarian]

Try This:

public int MONTH = 1;
public int YEAR = 2;
public int DAY = 3;

public int dateDiff(int interval, DateTime d1, DateTime d2){
if(d1 < d2){
//Swap the operators and then return.
//I expect the larger date to appear first
return dateDiff(interval, d2, d1);
}
years = d1.Year - d2.Year;
months = d1.Month - d2.Month;

if(interval == MONTH){
return (years * 12) + months;
}

if(interval == YEAR){
return years;
}
return ts.Days;
}