Create valid datetime object with validation

Question

I am creating date using following code

 try
 {
    newdatetime = new DateTime(2012, 2, 30);
    break;
 }
 catch (ArgumentOutOfRangeException)
 {
   // Try 29 Feb if not 28.
 }

The catch block is to catch the invalid date like 30 Feb. Is there any way to verify if the date is valid by speciying the parameters like (year, month, day)?

Use [DateTime.TryParse()](http://msdn.microsoft.com/en-us/library/system.datetime.tryparse.aspx) instead? — Bridge, Jul 02 '12 at 12:53
@TimSchmelter Good spot and I lol'd when I noticed my provided example is very similar to this - coincidence! — Adam Houldsworth, Jul 02 '12 at 13:01

Adam Houldsworth · Accepted Answer · 2012-07-02T13:16:31.033

Well, with months you know the valid range so you can constrain that manually. Years are obviously not constrained in the normal sense, but are instead limited by the amount that DateTime can actually hold (0001 to 9999).

With days, there is the DaysInMonth(int year, int month) method that can tell you the maximum days for the provided month. This also gives you the leap year.

With this information, you can create your own method to check the range based on the provided integers.

Something like:

public static bool AreValidDateValues(int year, int month, int day)
{
    if (month < 1 || month > 12)
        return false;

    if (year < DateTime.MinValue.Year || year > DateTime.MaxValue.Year)
        return false;

    var days = DateTime.DaysInMonth(year, month);

    if (day < 1 || day > days)
        return false;

    return true;
}

Or if you can't be bothered with that, convert the raw values into a string representation of a date and put that into DateTime.TryParse, which will give a true/false for the provided string - just be careful with culture-sensitive parsing.

score 1 · Answer 2 · answered Jul 02 '12 at 12:57

1

You can use DateTime.TryParse to perform the check :

DateTime d;
var isValid = DateTime.TryParse(String.Format("{0}/{1}/{2}", 2, 31, 2012), out d);
Console.WriteLine(isValid);

answered Jul 02 '12 at 12:57

Chandu

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That string format is open to different interpretations dependant on locale though. As per [this answer](http://stackoverflow.com/a/4719050/1220971) I'd suggest that you use `TryParseExact()`, specifying the format that you're creating the DateTime with. Otherwise you might end up with an `ArgumentOutOfRangeException` if the locale is expecting the month and day in a different order. – Bridge Jul 02 '12 at 13:03
@Bridge: Agreed. Will update the post with the alternate.. – Chandu Jul 02 '12 at 13:05

Create valid datetime object with validation

2 Answers2