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Need help validating date YYYY-MM-DD

looking for a regex in .Net for validating a date parameter
with following attributes
Accepts dates with format yyyy-mm-dd
date should be between (1753-01-01 and 9999-12-31)(both inclusive)

Appreciate your help.
Thanks
0
EmiliJ
Asked:
EmiliJ
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1 Solution
 
rockiroadsCommented:
What if you formatted your date using ToString as YYYYMMDD then check to see if its >= 17530101 and <= 99991231

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rockiroadsCommented:
date mask should be yyyyMMdd
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Anurag ThakurCommented:
if its a web application then i will recommend you to use a range validator
the sample is shown in the folowing EE link
http://www.experts-exchange.com/Programming/Languages/C_Sharp/Q_22864495.html
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CebikCommented:
too much code :( ?

 bool check(string s)
        {
            DateTime dt = DateTime.MinValue;
            try
            {
                DateTime.ParseExact(s, "yyyy-MM-dd", System.Globalization.CultureInfo.CurrentCulture);
                //or try parse exact
            }
            catch (Exception ex)
            {
                return false;
            }
 
            if (dt < new DateTime(1753, 01, 01))
                return false;
            if (dt > new DateTime(9999, 12, 31))
                return false;
 
            return true;
        }

Open in new window

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rockiroadsCommented:
an example

int iMyDate = Convert.ToInt32(dt.ToString("yyyyMMdd"));

if (iMyDate >= 17530101 && iMyDate <= 99991231)
{
    MessageBox.Show("Valid Date")
} else {
    MessageBox.Show("Invalid");
}

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CebikCommented:
or that..
i know that is'n regex..

bool Check(string s)
{
    DateTime dt = DateTime.MinValue;
    bool result = DateTime.TryParseExact(s, "yyyy-MM-dd", System.Globalization.CultureInfo.CurrentCulture, System.Globalization.DateTimeStyles.None, out dt);
 
    if (!result || (dt < new DateTime(1753, 01, 01)) || (dt > new DateTime(9999, 12, 31)))
        return false;
 
    return true;
}

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CebikCommented:
and final version..
good luck ;)

/// <summary>
/// Check range and return result and dateTime.
/// </summary>
/// <param name="s">input string</param>
/// <param name="dateTime">DateTime.MinValue if not correct!</param>
/// <returns>true or false</returns>
bool Check(string s, out DateTime dateTime)
{
    dateTime = DateTime.MinValue;
    bool result = DateTime.TryParseExact(s, "yyyy-MM-dd", System.Globalization.CultureInfo.CurrentCulture, System.Globalization.DateTimeStyles.None, out dateTime);
 
    if (!result || (dateTime < new DateTime(1753, 01, 01)) || (dateTime > new DateTime(9999, 12, 31)))
        return false;
 
    return true;
}

Open in new window

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EmiliJAuthor Commented:
Thanks for all reply. actually I am developing a web service and using regex expressions for validating parameters. I wanted to be consistent and that the reason I wish to have regex to validate date ranges.

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Anurag ThakurCommented:
can you please try my suggestion for web using range validator sample using EE
ID:24029346
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rockiroadsCommented:
You could use regex to perhaps check the format but your question of checking to see if its within a range, Im not sure if thats possible using regular expressions or is worth it. But you can use it to check for it to be in the format yyyyy-mm-dd

Im trying to get this expression to work but it seems to not recognise it as a valid sequence  http://www.dotnetspider.com/forum/85373-regular-expression-for-date-format-yyyy-mm-dd.aspx

And in code I have to try it out is

Regex rex = new Regex("(19|20)\d\d[- /.](0[1-9]|1[012])[- /.](0[1-9]|[12][0-9]|3[01])");

if (rex.IsMatch("2001-11-11").ToString())
{
    MessageBox.show("So far date in valid format");
} else {
    MessageBox.show("Date not in valid format");
}

But as I said, it is complaining about that expression in c#
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obrienslalomCommented:
I have the year portion of the regex validation functioning (I think).  I got a bit lazy so I didn't do the date/day validation (but I'd imagine you know how to do that).  If not, I can finish it for you.  Anyway, you can remove the ?: if you don't care where any capture groups go.

(?:(?:1[7-9](?:(?:(?<=7)(?:[5-9][3-9]))|(?:(?<=[8-9])(?:\d\d))))|(?:[2-9]\d{3}))-\d{2}-\d{2}
 
-------------------------------
Test data (* represent pass):
1752-01-01
1822-01-01  * 
1753-01-01  *
1794-01-01  *
8015-03-11  *
9999-12-31  *
10002-12-23

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rockiroadsCommented:
Ok, I couldnt get the date range in the regular expressions. Still working on it.
So a combination of regular expression and normal date range check



private bool isValidDate(String sDate)
{
      bool isValid = false;

      //yyyy-mm-dd format
      string pattern =  "\\d{4}([/-])\\d{1,2}\\1\\d{1,2}";
                  
      Regex rex = new Regex(pattern);

      if (rex.IsMatch(sDate))
      {
            try
            {
                  DateTime dt = DateTime.ParseExact(sDate,"yyyy-MM-dd",null);

                  int iMyDate = Convert.ToInt32(dt.ToString("yyyyMMdd"));

                  if (iMyDate >= 17530101  && iMyDate <= 99991231)
                  {
                        isValid = true;
                  }
            }
            catch (Exception)
            {
            }
      }

      return isValid;
}


and sample usage

String sDate = "2001-12-31";
bool isValid = isValidDate(sDate);

if (isValid)
{
      MessageBox.Show(sDate + " is valid");
}
else
{
      MessageBox.Show(sDate + " is not valid");
}
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