Regular Expression for Date (dd/mm/yyyy and dd-mm-yyyy) format in ASP.Net

Hi Mahesh1986,

Regular expressions should not be used for date validation. This will match date like strings, which can then be validated using a proper date library if needed.

Still i am providing you the ValidationExpression.

For dd/mm/yyyy - ValidationExpression="(0[1-9]|[12][0-9]|3[01])[/](0[1-9]|1[012])[/]\d{4}"

For dd-mm-yyyy - ValidationExpression="(0[1-9]|[12][0-9]|3[01])[-](0[1-9]|1[012])[-]\d{4}"

(0[1-9]|[12][0-9]|3[01]) For Day

(0[1-9]|1[012]) For Month

\d{4} For Year

[-] For -

[/] For /

HTML

<asp:TextBox runat="server" ID="txtDate1" placeholder="dd/mm/yyyy format only" />
<asp:RegularExpressionValidator ID="revDate1" ErrorMessage="DateFormat should be dd/mm/yyyy"
    ControlToValidate="txtDate1" runat="server" ValidationExpression="(0[1-9]|[12][0-9]|3[01])[/](0[1-9]|1[012])[/]\d{4}" />
<br />
<asp:TextBox runat="server" ID="txtDate2" placeholder="dd-mm-yyyy format only" />
<asp:RegularExpressionValidator ID="revDate2" ErrorMessage="DateFormat should be dd-mm-yyyy"
    ControlToValidate="txtDate2" runat="server" ValidationExpression="(0[1-9]|[12][0-9]|3[01])[-](0[1-9]|1[012])[-]\d{4}" />