?
Solved

How do I calculate due date with whole months?

Posted on 2009-05-07
4
Medium Priority
?
624 Views
Last Modified: 2013-12-17
I'm trying to calculate the due date of an invoice, and I have a date of invoice, days to due date (100) and I need to calculate due date with whole months:

For example:
if date of invoice = 07/05/2009 and days of due date = 120, then the due date calculated = 07/09/2009 (4 months exactly -whole months-).
My code:
 
DateTime invoiceDate=System.DateTime.Now();
int numberOfDays=100;
int numberOfMonths;
int restOfNumberOfDays;
Date dueDate;
 
if(wholeMonths)
{
    numberOfMonths = numberOfDays % 30;
    dueDate = dt.AddMonths(numberOfMonths);
    restOfNumberOfDays = numberOfDays - (numberOfMonths * 30);
    dueDate = dueDate.AddDays(restOfNumberOfDays);
}
 
This code would be correct if the month had 30 days long.

Open in new window

0
Comment
Question by:ReaL10
[X]
Welcome to Experts Exchange

Add your voice to the tech community where 5M+ people just like you are talking about what matters.

  • Help others & share knowledge
  • Earn cash & points
  • Learn & ask questions
  • 2
4 Comments
 
LVL 16

Accepted Solution

by:
CuteBug earned 900 total points
ID: 24324354
There is a DateDiff method in Visual Basic which returns the value in months.

Just go through this site for details
http://www.csharpfriends.com/Forums/ShowPost.aspx?PostID=52580

The decompiled code for DateDiff is provided there...

you need to convert it to C#.
Here is the code...
Public Shared Function DateDiff(ByVal Interval As DateInterval, ByVal Date1 As DateTime, ByVal Date2 As DateTime, ByVal Optional DayOfWeek As FirstDayOfWeek = 1, ByVal Optional WeekOfYear As FirstWeekOfYear = 1) As Long
Dim currentCalendar As Calendar
Dim span As TimeSpan = Date2.Subtract(Date1)
Select Case Interval
Case DateInterval.Year
currentCalendar = DateAndTime.CurrentCalendar
Return CLng((currentCalendar.GetYear(Date2) - currentCalendar.GetYear(Date1)))
Case DateInterval.Quarter
currentCalendar = DateAndTime.CurrentCalendar
Return CLng(((((currentCalendar.GetYear(Date2) - currentCalendar.GetYear(Date1)) * 4) + ((currentCalendar.GetMonth(Date2) - 1) / 3)) - ((currentCalendar.GetMonth(Date1) - 1) / 3)))
Case DateInterval.Month
currentCalendar = DateAndTime.CurrentCalendar
Return CLng(((((currentCalendar.GetYear(Date2) - currentCalendar.GetYear(Date1)) * 12) + currentCalendar.GetMonth(Date2)) - currentCalendar.GetMonth(Date1)))
Case DateInterval.DayOfYear, DateInterval.Day
Return CLng(Math.Round(Conversion.Fix(span.TotalDays)))
Case DateInterval.WeekOfYear
Date1 = Date1.AddDays(CDbl((0 - DateAndTime.GetDayOfWeek(Date1, DayOfWeek))))
Date2 = Date2.AddDays(CDbl((0 - DateAndTime.GetDayOfWeek(Date2, DayOfWeek))))
Return (CLng(Math.Round(Conversion.Fix(Date2.Subtract(Date1).TotalDays))) / 7)
Case DateInterval.Weekday
Return (CLng(Math.Round(Conversion.Fix(span.TotalDays))) / 7)
Case DateInterval.Hour
Return CLng(Math.Round(Conversion.Fix(span.TotalHours)))
Case DateInterval.Minute
Return CLng(Math.Round(Conversion.Fix(span.TotalMinutes)))
Case DateInterval.Second
Return CLng(Math.Round(Conversion.Fix(span.TotalSeconds)))
End Select
Throw New ArgumentException(Utils.GetResourceString("Argument_InvalidValue1", New String() { "Interval" }))
End Function 

Open in new window

0
 
LVL 16

Assisted Solution

by:CuteBug
CuteBug earned 900 total points
ID: 24324366
I think this is what they are doing for difference in months

private static int monthDifference(DateTime startDate, DateTime endDate)
{
int monthsApart = 12 * (startDate.Year - endDate.Year) + startDate.Month - endDate.Month;
return Math.Abs(monthsApart);
}

Open in new window

0
 
LVL 4

Assisted Solution

by:cauos
cauos earned 300 total points
ID: 24324389
there is an already method to add days to datetime objct in .Net, all what you have to do is add number of days to the method AddDays()

DateTime duedate = DateTime.Now
duedate = duedate.AddDays(120)

0
 
LVL 9

Assisted Solution

by:tculler
tculler earned 300 total points
ID: 24325458
Well, if you want every month to be exactly 30 days, you could use the following method:
System.DateTime CalculateDueDate(System.Int32 myDaysUntilDue)
{
     return System.DateTime.Now.AddMonths(myDaysUntilDue / 30);
}

Open in new window

0

Featured Post

Free Tool: Port Scanner

Check which ports are open to the outside world. Helps make sure that your firewall rules are working as intended.

One of a set of tools we are providing to everyone as a way of saying thank you for being a part of the community.

Question has a verified solution.

If you are experiencing a similar issue, please ask a related question

Many of us here at EE write code. Many of us write exceptional code; just as many of us write exception-prone code. As we all should know, exceptions are a mechanism for handling errors which are typically out of our control. From database errors, t…
For those of you who don't follow the news, or just happen to live under rocks, Microsoft Research released a beta SDK (http://www.microsoft.com/en-us/download/details.aspx?id=27876) for the Xbox 360 Kinect. If you don't know what a Kinect is (http:…
Have you created a query with information for a calendar? ... and then, abra-cadabra, the calendar is done?! I am going to show you how to make that happen. Visualize your data!  ... really see it To use the code to create a calendar from a q…
How to fix incompatible JVM issue while installing Eclipse While installing Eclipse in windows, got one error like above and unable to proceed with the installation. This video describes how to successfully install Eclipse. How to solve incompa…

649 members asked questions and received personalized solutions in the past 7 days.

Join the community of 500,000 technology professionals and ask your questions.

Join & Ask a Question