How to find the number of days between two dates in java or groovy?

Question

I have a method which uses following logic to calculate difference between days.

long diff = milliseconds2 - milliseconds1;
long diffDays = diff / (24 * 60 *         


        

Answer 1

In groovy all you need is:

date2 - date1

which returns an integer representing the number of days between the two dates.

Or if you need to guard against reversal of order between the two Date instances (the operation returns negative numbers when the first operand is earlier than the second):

Math.abs(date2 - date1)

The above examples use the groovy date.minus(date) operator implementation which returns the number of days between the two dates.

Example groovy shell session:

$ groovysh
Groovy Shell (2.4.8, JVM: 1.8.0_111)
Type ':help' or ':h' for help.

groovy:000> x = new Date(1486382537168)
===> Mon Feb 06 13:02:17 CET 2017

groovy:000> y = new Date(1486000000000)
===> Thu Feb 02 02:46:40 CET 2017

groovy:000> x - y
===> 4

or if you need a method:

int daysBetween(date1, date2) {
    Math.abs(date2 - date1)
}