If you are taking user input and you need to ensure that the user enters the date in valid format as we specified. d – Represents minimum digit in the range of 1 to 2.You can validate the user input at the time of form submission or on on Blur event. Month and Date can be either be single digit or multiple digit.There are many ways to do this, with perhaps the most obvious being finding the difference between the date of birth and the current date using library functions, and checking that this difference is more than 18 years.
It is very important to validate the data supplied by the user through a form before you process it. In the following examples, a Java Script function is used to check a valid date format against a regular expression.This approach is perhaps less desirable than the approach we have described, because there is no database activity involved in our example, and database activity adds unnecessary overhead.However, if one or more dates are extracted in the script from a database, My SQL date and time functions are a useful alternative.ereg("^([0-9])/([0-9])/([0-9])$", $form Vars["dob"], $parts)) // Check the format $error String .= "The date of birth is not a valid date in the " . checkdate($parts,$parts,$parts)) $error String .= "The date of birth is invalid. "Please check that the month is between 1 and 12, " . The second check uses a regular expression to check whether the date consists of numbers and if it matches the template fields."and the day is valid for that month."; elseif (intval($parts) , and no further checks of the date are made. The fifth and final check tests if the user is 18 years of age or older.For example, one approach is to use the My SQL functions described in Chapter 3 through an SQL query.