java.time.Instant - Representing a Moment of Time

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∟Java Date-Time API

∟java.time.Instant - Representing a Moment of Time

This section describes the java.time.Instant class that represents a moment of time expressed in 2 components, Epoch-Second and Nanosecond-of-Second.

java.time.Instant represents an instantaneous moment of time with a resolution of nanosecond. The moment of time is represented by a java.time.Instant object with 2 components:

Epoch-Second - Representing the number of seconds passed between this moment and the Unix Epoch point, 1970-01-01T00:00:00Z.
Nanosecond-of-Second - Representing the fraction of a second passed between this moment and last second.

The java.time.Instant class is designed mainly for measuring absolute time and duration for scientific purposes. It does not contain any calendar, timezone or UTC offset information.

Main methods offered on the java.time.Instant class are:

ofEpochSecond() - A static method returning an Instant object representing the moment of time when the given number of seconds is passed since the Unix Epoch point and the given number of nanoseconds is passed since the last second. Note that there are no constructors in Instant class. So "new Instant()" is not a valid expression.
getEpochSecond() - An object method returning the Epoch-Second value of this Instant object. The Epoch-Second value is the number of whole seconds passed between the moment of time represented by this Instant object and the Unix Epoch point of time, which can be expressed in ISO 8601 date and time format as "1970-01-01T00:00:00Z".
getNano() - An object method returning the Nanosecond-of-Second value of this Instant object. The Nanosecond-of-Second value is the fraction of a second passed between the moment of time represented by this Instant object and last whole second passed since the Unix Epoch point of time.
get() - An object method returning the value of a given temporal field, NANO_OF_SECOND, MICRO_OF_SECOND, MILLI_OF_SECOND, or INSTANT_SECONDS from this Instant object.
toString() - An object method returning a string representing this Instant object in ISO 8601 date and time format based on ISO 8601 calendar and Coordinated Universal Time (UTC) standard with nanoseconds precision. Here is an example of toString() output, "2014-04-01T04:41:10.123456789Z".
plus() - An object method returns a copy of this Instant object with additional time added in NANOS, MICROS, MILLIS, SECONDS, MINUTES, HOURS, HALF_DAYS, or DAYS unit. Note that the plus() cannot be used to construct time instant by adding time in calendar units like years or months.
minus() - An object method returns a copy of this Instant object with additional time removed in NANOS, MICROS, MILLIS, SECONDS, MINUTES, HOURS, HALF_DAYS, or DAYS unit. Note that the minus() cannot be used to construct time instant by subtracting time in calendar units like years or months.
with() - An object method returns a copy of this Instant object with a new value set on a specified field, NANO_OF_SECOND, MICRO_OF_SECOND, MILLI_OF_SECOND, or INSTANT_SECONDS.
ofEpochMilli() - A static method returning an Instant object representing the moment calculated by adding the specified milliseconds to the Unix Epoch point of time.
parse() - A static method returning an Instant object representing a moment of time constructed by parsing the given character sequence using the ISO 8601 date and time format.
now() - A static method returning an Instant object representing the current moment based on the system clock time.

Table of Contents

About This JDK Tutorial Book

JDK (Java Development Kit)

►Java Date-Time API

What Is Date-Time API

►java.time.Instant - Representing a Moment of Time

java.time.Instant Usage Examples

java.time.Instant - get(INSTANT_SECONDS) Error

Converting java.util.Date to java.time.Instant

java.time.ZonedDateTime - Calendar and Timezone

java.time.ZonedDateTime Usage Examples

Converting java.util.GregorianCalendar to java.time.ZonedDateTime

java.time.OffsetDateTime - Calendar and UTC Offset

java.time.OffsetDateTime Usage Examples

java.time.LocalDateTime - Local Date and time without Timezone

Partial Date and Time Objects and Classes

java.time.format.DateTimeFormatter - Date-Time Strings

java.time.Duration - Time Durations

java.time.Duration Usage Examples

java.time.Period - Periods in Days and Months

java.time.Period Usage Examples

Date, Time and Calendar Classes

Date and Time Object and String Conversion

Number Object and Numeric String Conversion

Locales, Localization Methods and Resource Bundles

Calling and Importing Classes Defined in Unnamed Packages

HashSet, Vector, HashMap and Collection Classes

Character Set Encoding Classes and Methods

Character Set Encoding Maps

Encoding Conversion Programs for Encoded Text Files

Socket Network Communication

Datagram Network Communication

DOM (Document Object Model) - API for XML Files

SAX (Simple API for XML)

DTD (Document Type Definition) - XML Validation

XSD (XML Schema Definition) - XML Validation

XSL (Extensible Stylesheet Language)

Message Digest Algorithm Implementations in JDK

Private key and Public Key Pair Generation

PKCS#8/X.509 Private/Public Encoding Standards

Digital Signature Algorithm and Sample Program

"keytool" Commands and "keystore" Files

KeyStore and Certificate Classes

Secret Key Generation and Management

Cipher - Encryption and Decryption

The SSL (Secure Socket Layer) Protocol

SSL Socket Communication Testing Programs

SSL Client Authentication

HTTPS (Hypertext Transfer Protocol Secure)

Outdated Tutorials

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