How to parse a date?

java

date-handling

date-formatting

java-date-api

byNikita Barsukov·Jan 25, 2025

Quickly parse a date in Java with LocalDate.parse utilizing a predefined formatter:

// Now you're becoming a time traveler
import java.time.LocalDate;
import java.time.format.DateTimeFormatter;

// here's your DeLorean's dashboard
String dateStr = "2023-04-01";
DateTimeFormatter fmt = DateTimeFormatter.ISO_LOCAL_DATE;
LocalDate date = LocalDate.parse(dateStr, fmt);

The ISO_LOCAL_DATE takes care of yyyy-MM-dd formats. For more eccentric formats, use DateTimeFormatter.ofPattern. Just don't forget your flux capacitor.

Robust Date Handling — When Special Cases Activates Your Jetpack

Date-Time Mozaic: Using `SimpleDateFormat`:

For dates like "Thu Jun 18 20:56:02 EDT 2009", make good use of SimpleDateFormat with the matching pattern:

// Dust off your ancient ruins map
import java.text.SimpleDateFormat;
import java.text.ParseException;
import java.util.Date;

// The relic no one could decipher
String complexDateStr = "Thu Jun 18 20:56:02 EDT 2009";

// The Rosetta stone
SimpleDateFormat oldFormatter = new SimpleDateFormat("EEE MMM dd HH:mm:ss zzz yyyy");

try {
    // History disclosed!
    Date oldDate = oldFormatter.parse(complexDateStr); 
} catch (ParseException e) {
    // oops, better luck next century
    e.printStackTrace();
}

`java.time` and `DateTimeFormatter`: The Time Machine Blueprint

Switch to java.time with DateTimeFormatter for a robust date-time navigation. If your legacy clock is still ticking:

// The wormhole is ready!
import java.time.Instant;
import java.util.Date;

// Initiating time jump...
Instant instant = dateTime.toInstant();
Date legacyDate = Date.from(instant);

TimeZone: Time Travel Made Easier

You can set the timezone in SimpleDateFormat for smooth time-travel across different time zones:

// Go everywhere in every time!
import java.util.TimeZone;

// Your universal key
SimpleDateFormat sdfWithTz = new SimpleDateFormat("yyyy-MM-dd'T'HH:mm:ss");
sdfWithTz.setTimeZone(TimeZone.getTimeZone("UTC"));

Dealing with User-Generated Wormholes

While dealing with user-provided data, validate the provided date format and adjust your parsing mechanism accordingly:

// Users always surprise!
import net.sourceforge.jdatepicker.impl.JDatePickerImpl;

// Wormhole entrance?
JDatePickerImpl datePicker = //...
Date selectedDate = (Date) datePicker.getModel().getValue();