Calculate days between two Dates in Java 8

I know there are lots of questions on SO about how to get Dates 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:

1. Prevent errors from date savetime
2. Inputs are two Date objects (without time, I know about LocalDateTime, but I need to do this with Date instances)

If you want logical calendar days, use DAYS.between() method from java.time.temporal.ChronoUnit:

LocalDate dateBefore;
LocalDate dateAfter;
long daysBetween = DAYS.between(dateBefore, dateAfter);

If you want literal 24 hour days, (a duration), you can use the Duration class instead:

LocalDate today = LocalDate.now()
LocalDate yesterday = today.minusDays(1);
// Duration oneDay = Duration.between(today, yesterday); // throws an exception
Duration.between(today.atStartOfDay(), yesterday.atStartOfDay()).toDays() // another option

For more information, refer to this document.

Based on VGR's comments here is what you can use:

ChronoUnit.DAYS.between(firstDate, secondDate)

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));

Output:

Until christmas: P5M21D
Until christmas (with crono): 174

as mentioned at comment - first untill() returns Period.

Snippet from the documentation:

A date-based amount of time in the ISO-8601 calendar system, such as '2 years, 3 months and 4 days'.
This class models a quantity or amount of time in terms of years, months, and days. See Duration for the time-based equivalent to this class.