How do I discover the Quarter of a given Date?

Question

Given a java.util.Date object how do I go about finding what Quarter it\'s in?

Assuming Q1 = Jan Feb Mar, Q2 = Apr, May, Jun, etc.

Answer 1

tl;dr

YearQuarter
.from(
    LocalDate.of( 2018 , 1 , 23 ) 
)

ThreeTen-Extra

The Answer by abdmob is correct: Using java.time is the wise way to go.

In addition, the ThreeTen-Extra project extends java.time with additional classes. This project is a proving ground for possible future additions to java.time.

Its useful classes include:

• Quarter
• YearQuarter

Current quarter

To get the current quarter, specify a time zone. Determining a quarter means determining a date. And determining a date means specifying a time zone. For any given moment, the date varies around the globe by zone. Specify by using a proper time zone name in form of continent/region. Never use the 3-4 letter abbreviations such as EST or IST.

ZoneId z = ZoneId.of( "America/Montreal" );
YearQuarter yq = YearQuarter.now( z );

Given a java.util.Date

If given a java.util.Date first convert to a java.time type. The Instant class represents a moment on the timeline in UTC with a resolution of nanoseconds.

Instant instant = myUtilDate.toInstant();

Assign a time zone to get a ZoneDateTime.

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

Generate a YearQuarter from that ZonedDateTime.

YearQuarter yq = YearQuarter.from( zdt );

Use throughout your code

You should be passing around instances of YearQuarter rather than mere numbers or strings. Using objects provides type-safety, ensures valid values, and makes your code more self-documenting.

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About java.time

The java.time framework is built into Java 8 and later. These classes supplant the troublesome old legacy date-time classes such as java.util.Date, Calendar, & SimpleDateFormat.

To learn more, see the Oracle Tutorial. And search Stack Overflow for many examples and explanations. Specification is JSR 310.

The Joda-Time project, now in maintenance mode, advises migration to the java.time classes.

You may exchange java.time objects directly with your database. Use a JDBC driver compliant with JDBC 4.2 or later. No need for strings, no need for java.sql.* classes.

Where to obtain the java.time classes?

• Java SE 8, Java SE 9, Java SE 10, Java SE 11, and later - Part of the standard Java API with a bundled implementation.
  • Java 9 adds some minor features and fixes.
• Java SE 6 and Java SE 7
  • Most of the java.time functionality is back-ported to Java 6 & 7 in ThreeTen-Backport.
• Android
  • Later versions of Android bundle implementations of the java.time classes.
  • For earlier Android (<26), the ThreeTenABP project adapts ThreeTen-Backport (mentioned above). See How to use ThreeTenABP….

The ThreeTen-Extra project extends java.time with additional classes. This project is a proving ground for possible future additions to java.time. You may find some useful classes here such as Interval, YearWeek, YearQuarter, and more.

Answer 2

with java8 you may use formatter:

import java.time.format.DateTimeFormatter
import java.time.LocalDate

println("withQuarter: " + LocalDate.of("2016".toInt,"07".toInt,1).format(DateTimeFormatter.ofPattern("yyyyQMM")))

withQuarter: 2016307