javajava-8

How to calculate the number of days in a period?


For the following Period calculation:

Period.between(LocalDate.of(2015, 8, 1), LocalDate.of(2015, 9, 2))

the result is:

P1M1D

This is equivalent to 31 days + 1 day = 32 days.

For this Period:

Period.between(LocalDate.of(2015, 8, 1), LocalDate.of(2015, 10, 2))

the result is:

P2M1D

This is equivalent to: 31 days (in August) + 30 days (in September) + 1 (in October) = 62 days

Is there a method in the java.time package which will give the number of days in a Period? I can't find one. Not sure if I have overlooked anything or if it is just plain not there.


Solution

  • From the documentation:

    To define an amount of time with date-based values (years, months, days), use the Period class. The Period class provides various get methods, such as getMonths, getDays, and getYears.To present the amount >of time measured in a single unit of time, such as days, you can use the ChronoUnit.between method.

    LocalDate today = LocalDate.now();
    LocalDate birthday = LocalDate.of(1960, Month.JANUARY, 1);
    
    Period p = Period.between(birthday, today);
    long p2 = ChronoUnit.DAYS.between(birthday, today);
    System.out.println("You are " + p.getYears() + " years, " + p.getMonths() +
                       " months, and " + p.getDays() +
                       " days old. (" + p2 + " days total)");
    

    The code produces output similar to the following:

    You are 53 years, 4 months, and 29 days old. (19508 days total)