Why does converting java.util.Date to java.sql.Date result in inaccurate dates?

Question

I am converting java.util.Date to java.sql.date in order to insert date of birth into mysql database.

However, entering 2001-04-03 always results in java.sql.Date being 2000-12-31

BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
System.out.println("Enter dob(YYYY-MM-DD) :");
String date = br.readLine();

SimpleDateFormat dateFormat = new SimpleDateFormat("YYYY-MM-DD");
            
java.util.Date util_dob = dateFormat.parse(date);
            
java.sql.Date dob = new java.sql.Date(util_dob.getTime());

Enter: 2001-04-03

Output: 2000-12-31

Expectation: 2001-04-03

Answer 1

Your format string is incorrect.

Please view the documentation for SimpleDateFormat: https://docs.oracle.com/en/java/javase/11/docs/api/java.base/java/text/SimpleDateFormat. html

• Capital letters Y: Pattern letters representing anniversary
• Capital letters M: Pattern letters representing months of the year (correct)
• Capital letters D: Pattern letters representing the number of days in the year

You should use lowercase letters y and lowercase letters d.

• Lowercase letters y: Pattern letters representing year
• Lowercase letters d: Pattern letters representing the number of days in the month

I think your conversion should use the following pattern:

SimpleDateFormat dateFormat = new SimpleDateFormat("yyyy-MM-dd");