index > Windows Forms General > calculating dateTime (now and endDate)

calculating dateTime (now and endDate)

On my form I have a monthCalendar with which I enter an EndDate (when something needs to happen) into a database. The time when I enter is now. So I have 2 values. Now and EndDate.

How to calculate how many days, months, years is between these two values? I would like to put the 3rd value (the difference between 1st and 2nd) into a textBox!

I am a rookie at C#, so please don`t be mad if my questions goona sound stupid...

Mitja Bonca Wednesday, June 10, 2009 9:17 AM

            DateTime dt1 = DateTime.Now;
            DateTime dt2 = <EndDate>

            DateTime dtSpan = new DateTime();

            TimeSpan span = new TimeSpan();

            span = dt2.Subtract(dt1);

            double numDays = span.TotalDays;

This would give you number of days. And, so you can carry on.

Regards, Lakra :) - If the post is helpful or answers your question, please mark it as such.

Marked As Answer byLinda LiuMSFT, ModeratorFriday, June 19, 2009 10:44 AM

Abhijeet Lakra Wednesday, June 10, 2009 9:30 AM

One more valuable point of advice:
Suppose, nowDateTime = 12-Apr-2008 10:00:00 AM and EndDateTime = 14-Apr-2008 08:00:00 AM
In this case, how many number of days difference do you expect as answer for your Application?
If you expect 2 days, well the output by C# would be 1 day because it also considers time(HH:MM:SS) into account.

So, what you can do is build your own DateTime value before processing, something as:

            DateTime dtNow = new DateTime(DateTime.Now.Year, DateTime.Now.Month, DateTime.Now.Day);
            dt2 = new DateTime(dt2.Year, dt2.Month, dt2.Day);

This would have the common default time for both the dateTime values.

Regards, Lakra :) - If the post is helpful or answers your question, please mark it as such.

Marked As Answer byLinda LiuMSFT, ModeratorFriday, June 19, 2009 10:45 AM

Abhijeet Lakra Wednesday, June 10, 2009 9:50 AM

You can use DateTime.Now.Subtract to get another datetime object.

Thanks, A.m.a.L .Net Goodies
Remember to click "mark as answered" when you get a correct reply to your question

A.m.a.L - aditi.com - Think Product Wednesday, June 10, 2009 9:25 AM

Hello mitja,
By calculating TimeSpan you can get year,months..
try like this,

DateTime dtNow;

DateTime dtEnd;

TimeSpan ts = dtEnd.Subtract(dtNow);

int year= ts.Days / 365;
int weeks = ts.Days/7;

NareshG Wednesday, June 10, 2009 9:27 AM

            DateTime dt1 = DateTime.Now;
            DateTime dt2 = <EndDate>

            DateTime dtSpan = new DateTime();

            TimeSpan span = new TimeSpan();

            span = dt2.Subtract(dt1);

            double numDays = span.TotalDays;

This would give you number of days. And, so you can carry on.

Regards, Lakra :) - If the post is helpful or answers your question, please mark it as such.

Marked As Answer byLinda LiuMSFT, ModeratorFriday, June 19, 2009 10:44 AM

Abhijeet Lakra Wednesday, June 10, 2009 9:30 AM

            DateTime dtNow = new DateTime(DateTime.Now.Year, DateTime.Now.Month, DateTime.Now.Day);
            dt2 = new DateTime(dt2.Year, dt2.Month, dt2.Day);

This would have the common default time for both the dateTime values.

Regards, Lakra :) - If the post is helpful or answers your question, please mark it as such.