I know there are lots of questions on SO about how to get Date
s in Java, but I want an example using new Java 8 Date
API. I also know about the JodaTime library, but I want a method without relying on external libraries.
The function needs to be compliant with these restrictions:
Date
objects (without time, I know about LocalDateTime
, but I need to do this with Date
instances)This question is related to
java
java-8
java-time
days
date-difference
Use the DAYS in enum java.time.temporal.ChronoUnit . Below is the Sample Code :
Output : *Number of days between the start date : 2015-03-01 and end date : 2016-03-03 is ==> 368. **Number of days between the start date : 2016-03-03 and end date : 2015-03-01 is ==> -368*
package com.bitiknow.date;
import java.time.LocalDate;
import java.time.temporal.ChronoUnit;
/**
*
* @author pradeep
*
*/
public class LocalDateTimeTry {
public static void main(String[] args) {
// Date in String format.
String dateString = "2015-03-01";
// Converting date to Java8 Local date
LocalDate startDate = LocalDate.parse(dateString);
LocalDate endtDate = LocalDate.now();
// Range = End date - Start date
Long range = ChronoUnit.DAYS.between(startDate, endtDate);
System.out.println("Number of days between the start date : " + dateString + " and end date : " + endtDate
+ " is ==> " + range);
range = ChronoUnit.DAYS.between(endtDate, startDate);
System.out.println("Number of days between the start date : " + endtDate + " and end date : " + dateString
+ " is ==> " + range);
}
}
I know this question is for Java 8, but with Java 9 you could use:
public static List<LocalDate> getDatesBetween(LocalDate startDate, LocalDate endDate) {
return startDate.datesUntil(endDate)
.collect(Collectors.toList());
}
Get number of days before Christmas from current day , try this
System.out.println(ChronoUnit.DAYS.between(LocalDate.now(),LocalDate.of(Year.now().getValue(), Month.DECEMBER, 25)));
Use the class or method that best meets your needs:
A Duration measures an amount of time using time-based values (seconds, nanoseconds).
A Period uses date-based values (years, months, days).
The ChronoUnit.between method is useful when you want to measure an amount of time in a single unit of time only, such as days or seconds.
https://docs.oracle.com/javase/tutorial/datetime/iso/period.html
Here you go:
public class DemoDate {
public static void main(String[] args) {
LocalDate today = LocalDate.now();
System.out.println("Current date: " + today);
//add 1 month to the current date
LocalDate date2 = today.plus(1, ChronoUnit.MONTHS);
System.out.println("Next month: " + date2);
// Put latest date 1st and old date 2nd in 'between' method to get -ve date difference
long daysNegative = ChronoUnit.DAYS.between(date2, today);
System.out.println("Days : "+daysNegative);
// Put old date 1st and new date 2nd in 'between' method to get +ve date difference
long datePositive = ChronoUnit.DAYS.between(today, date2);
System.out.println("Days : "+datePositive);
}
}
Based on VGR's comments here is what you can use:
ChronoUnit.DAYS.between(firstDate, secondDate)
If the goal is just to get the difference in days and since the above answers mention about delegate methods would like to point out that once can also simply use -
public long daysInBetween(java.time.LocalDate startDate, java.time.LocalDate endDate) {
// Check for null values here
return endDate.toEpochDay() - startDate.toEpochDay();
}
get days between two dates date is instance of java.util.Date
public static long daysBetweenTwoDates(Date dateFrom, Date dateTo) {
return DAYS.between(Instant.ofEpochMilli(dateFrom.getTime()), Instant.ofEpochMilli(dateTo.getTime()));
}
If startDate and endDate are instance of java.util.Date
We can use the between( ) method from ChronoUnit enum:
public long between(Temporal temporal1Inclusive, Temporal temporal2Exclusive) {
//..
}
ChronoUnit.DAYS count days which completed 24 hours.
import java.time.temporal.ChronoUnit;
ChronoUnit.DAYS.between(startDate.toInstant(), endDate.toInstant());
//OR
ChronoUnit.DAYS.between(Instant.ofEpochMilli(startDate.getTime()), Instant.ofEpochMilli(endDate.getTime()));
import java.time.LocalDate;
import java.time.temporal.ChronoUnit;
LocalDate dateBefore = LocalDate.of(2020, 05, 20);
LocalDate dateAfter = LocalDate.now();
long daysBetween = ChronoUnit.DAYS.between(dateBefore, dateAfter);
long monthsBetween= ChronoUnit.MONTHS.between(dateBefore, dateAfter);
long yearsBetween= ChronoUnit.YEARS.between(dateBefore, dateAfter);
System.out.println(daysBetween);
You can use until()
:
LocalDate independenceDay = LocalDate.of(2014, Month.JULY, 4);
LocalDate christmas = LocalDate.of(2014, Month.DECEMBER, 25);
System.out.println("Until christmas: " + independenceDay.until(christmas));
System.out.println("Until christmas (with crono): " + independenceDay.until(christmas, ChronoUnit.DAYS));
You can use DAYS.between
from java.time.temporal.ChronoUnit
e.g.
import java.time.temporal.ChronoUnit;
public long getDaysCountBetweenDates(LocalDate dateBefore, LocalDate dateAfter) {
return DAYS.between(dateBefore, dateAfter);
}
Everyone is saying to use ChronoUnit.DAYS.between but that just delegates to another method you could call yourself. So you could also do firstDate.until(secondDate, ChronoUnit.DAYS)
.
The docs for both actually mention both approaches and say to use whichever one is more readable.
Source: Stackoverflow.com