Published 18 Sep, 2022

Java - How to get the current date and time

Category Java
Modified : Sep 29, 2022
210

How do I get the current date and time in Java?

I am looking for something that is equivalent to DateTime.Now from C#.

Answers

There are 4 suggested solutions here and each one has been listed below with a detailed description. The following topics have been covered briefly such as Datetime, Java. These have been categorized in sections for a clear and precise explanation.

379

Just construct a new Date object without any arguments; this will assign the current date and time to the new object.

import java.util.Date;

Date d = new Date();

In the words of the Javadocs for the zero-argument constructor:

Allocates a Date object and initializes it so that it represents the time at which it was allocated, measured to the nearest millisecond.

Make sure you're using java.util.Date and not java.sql.Date -- the latter doesn't have a zero-arg constructor, and has somewhat different semantics that are the topic of an entirely different conversation. :)


82

tl;dr

Instant.now()

java.time

The java.util.Date class has been outmoded by the new java.time package (Tutorial) in Java 8 and later. The old java.util.Date/.Calendar classes are notoriously troublesome, confusing, and flawed. Avoid them.

ZonedDateTime

Get the current moment in java.time.

ZonedDateTime now = ZonedDateTime.now();

A ZonedDateTime encapsulates:

  • Date.
  • Time-of-day, with a fraction of a second to nanosecond resolution.
  • Time zone.

If no time zone is specified, your JVM’s current default time zone is assigned silently. Better to specify your desired/expected time zone than rely implicitly on default.

ZoneId z = ZoneId.of( "Pacific/Auckland" );
ZonedDateTime zdt = ZonedDateTime.now( z );

UTC

Generally better to get in the habit of doing your back-end work (business logic, database, storage, data exchange) all in UTC time zone. The code above relies implicitly on the JVM’s current default time zone.

The Instant class represents a moment in the timeline in UTC with a resolution of nanoseconds.

Instant instant = Instant.now();

The Instant class is a basic building-block class in java.time and may be used often in your code.

When you need more flexibility in formatting, transform into an OffsetDateTime. Specify a ZoneOffset object. For UTC use the handy constant for UTC.

OffsetDateTime odt = instant.atOffset( ZoneOffset.UTC );

Time Zone

You easily adjust to another time zone for presentation to the user. Use a proper time zone name, never the 3-4 letter codes such as EST or IST.

ZoneId z = ZoneId.of( "America/Montreal" );
ZonedDateTime nowMontreal = instant.atZone( z );

Generate a String representation of that date-time value, localized.

String output = DateTimeFormatter
    .ofLocalizedDate( FormatStyle.FULL )
    .withLocale( Locale.CANADA_FRENCH )
    .format ( nowMontreal );

Instant

Or, to stay in UTC, use Instant. An Instant object represents a moment on the timeline, to nanosecond resolution, always in UTC. This provides the building block for a zoned date-time, along with a time zone assignment. You can think of it conceptually this way:

ZonedDateTime = Instant + ZoneId

You can extract an Instant from a ZonedDateTime.

Instant instantNow = zdt.toInstant();

You can start with an Instant. No need to specify a time zone here, as Instant is always in UTC.

Instant now = Instant.now();

65

I prefer using the Calendar object.

Calendar now = GregorianCalendar.getInstance()

I find it much easier to work with. You can also get a Date object from the Calendar.

http://java.sun.com/javase/6/docs/api/java/util/GregorianCalendar.html


55

In Java 8 it's:

ZonedDateTime dateTime = ZonedDateTime.now();