Formatting dates in Java

In this post I will write about formatting dates in Java in different formats (patterns).

The Java classes that I will be using in the examples are:

• java.util.Date
• java.text.Format
• java.text.SimpleDateFormat

The class Date represents a specific instant in time, with millisecond precision.

Format is an abstract base class for formatting locale-sensitive information such as dates, messages, and numbers.

SimpleDateFormat is a concrete class for formatting and parsing dates in a locale-sensitive manner. It allows for formatting (date -> text), parsing (text -> date), and normalization. SimpleDateFormat allows you to start by choosing any user-defined patterns for date-time formatting.

A pattern of special characters is used to specify the format of the date. This example demonstrates some of the characters. For a complete listing, see the javadoc documentation for the SimpleDateFormat class.

Note: default locale (which, in the author's case) is Locale.ENGLISH. If the example is run in a different locale, the text (e.g., month names) will not be there: This example formats dates using the  same.

   

    Format formatter; 
    
    // The year 
    formatter = new SimpleDateFormat("yy");    // 02 
    formatter = new SimpleDateFormat("yyyy");  // 2002 
    
    // The month 
    formatter = new SimpleDateFormat("M");     // 1 
    formatter = new SimpleDateFormat("MM");    // 01 
    formatter = new SimpleDateFormat("MMM");   // Jan 
    formatter = new SimpleDateFormat("MMMM");  // January 
    
    // The day 
    formatter = new SimpleDateFormat("d");     // 9 
    formatter = new SimpleDateFormat("dd");    // 09 
    
    // The day in week 
    formatter = new SimpleDateFormat("E");     // Wed 
    formatter = new SimpleDateFormat("EEEE");  // Wednesday 
    
    // Get today's date 
    Date date = new Date(); 
    
    // Some examples 
    formatter = new SimpleDateFormat("MM/dd/yy"); 
    String s = formatter.format(date); 
    // 01/09/02 
    
    formatter = new SimpleDateFormat("dd-MMM-yy"); 
    s = formatter.format(date); 
    // 29-Jan-02