<!DOCTYPE html>
<html>
<body>

<form runat="server">
Enter a date between 2005-01-01 and 2005-12-31:
<br>
<asp:TextBox id="tbox1" runat="server" />
<br><br>
<asp:Button Text="Submit" runat="server" />
<br><br>
<asp:RangeValidator
ControlToValidate="tbox1"
MinimumValue="2005-01-01"
MaximumValue="2005-12-31"
Type="Date"
EnableClientScript="false"
Text="The date must be between 2005-01-01 and 2005-12-31!"
runat="server" />
</form>

</body>
</html>