minimum date of the year

I have one text box and i have to show minim开发者_JAVA百科um date of the current year in that texbox

that means: suppose consider if i select current_time (09/11/2009) then(01/01/2009) should be shown in text box

awaiting ur response

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You just want to construct a new DateTime with the same year, and other parameters set to one (for first day and month).

var currentDateTime = DateTime.Now; // or whatever else
var firstDayOfYear = new DateTime(currentDateTime.Year, 1, 1);

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Edit: As Noldorin points out, the simplest and most terse solution is something like this:

var firstDayOfYear = new DateTime(DateTime.Today.Year, 1, 1);

My old answer:

This should do it.

var now = DateTime.Now
var firstDayOfYear = now.Subtract(TimeSpan.FromDays(now.DayOfYear - 1)).Date

Edit: Actually this would be a bit cleaner:

var today = DateTime.Today
var firstDayOfYear = today.Subtract(TimeSpan.FromDays(today.DayOfYear - 1))

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I have had to solve this same problem in the past. In the end, I decided to create an Extension Methods class for the DateTime class to encapsulate and test the albeit simple functionality.

public static class DateTimeExtensions
{
    public static DateTime GetFirstDayOfYear(this DateTime date)
    {
        return new DateTime(date.Year, 1, 1);
    }
}

Now all I would have to do to get the date required is

DateTime selectedDate = DateTime.Today;
DateTime firstDayOfYear = selectedDate.GetFirstDayOfYear();

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Assuming you can get a DateTime object from the textbox (e.g. DateTime.Parse(...)) you can do this:

DateTime inputDate = DateTime.Parse(textBox.Text);
DateTime outputDate = new DateTime(inputDate.Year, 1, 1);