Check if date is older than x days (business days only)

Question

public class App {

    public static void main(String[] args) {
        final String cobDate = "2021-04-08";
        final String recordDate = "2020-12-01";
    }

    public static ZonedDateTime getDate(String date, DateTimeFormatter formatter) {
        LocalDate localDate = LocalDate.parse(date, formatter);
        return localDate.atStartOfDay(ZoneId.of(ZoneOffset.UTC.getId()));
    }
}

I am using java 8 and I want to check that the age of recordDate is greater than 5 days or not. But not from today but 5 days older than cobDate? How can I implement this and perhaps by using the already existing utility method I have that returns a ZoneDateTime? It should exclude weekends (e.g. Saturday & Sunday) and only consider business days.

Some Scenarios:

cobDate: 08/04/2021 recordDate: 08/04/2021 ==> false >> not older than 5 days

cobDate: 08/04/2021 recordDate: 31/03/2021 ==> true>> older than 5 days

cobDate: 08/04/2021 recordDate: 02/04/2021 ==> false >> not older than 5 days

"only consider business days" - would holidays need to be excluded as well? If not, calculating the number of days between 2 dates and subtracting the number of saturdays and sundays should be fairly straight forward using the java.time api — Thomas, Apr 08 '21 at 10:14
I've added an answer to the "duplicate" question which you might want to check out. There is no need to iterate although if you're only interested in "older than 5 days or not" you could simply iterate backwards starting at `cobDate` and count business days until you hit a value > 5 or `recordDate`. If record date is years in the past there's no need to iterate to know it's been 100s or 1000s of days since then (even if you need to know that there's no need to iterate). — Thomas, Apr 08 '21 at 12:12

Panagiotis Bougioukos · Accepted Answer · 2021-04-08T10:44:53.903

2

private static long countBusinessDaysBetween(LocalDate startDate, LocalDate endDate) 
    {
        if (startDate == null || endDate == null) {
            throw new IllegalArgumentException("Invalid method argument(s) to countBusinessDaysBetween(" + startDate
                    + "," + endDate);
        }

        if (startDate.isAfter(endDate)) {
           throw new IllegalArgumentException("Start Date must be before End Date");
        }
 
        Predicate<LocalDate> isWeekend = date -> date.getDayOfWeek() == DayOfWeek.SATURDAY
                || date.getDayOfWeek() == DayOfWeek.SUNDAY;
 
        long daysBetween = ChronoUnit.DAYS.between(startDate, endDate);
 
        long businessDays = Stream.iterate(startDate, date -> date.plusDays(1)).limit(daysBetween)
                .filter(isWeekend.negate()).count();
        return businessDays;
    }

From a very good article where I have just removed holidays check and added a constraint that endDate must always be after startDate

calculate business days

Then you can just do

public boolean isOlderThanXDays(int xDays, LocalDate startDate, LocalDate endDate) {
      return (YourClassName.countBusinessDaysBetween(startDate, endDate) > xDays)
  }

edited Apr 08 '21 at 10:44

answered Apr 08 '21 at 10:26

Panagiotis Bougioukos

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in this case startDate is cobDate? and endDate is recordDate which I want to check is greater than 5 days from cobDate or not ? – M06H Apr 08 '21 at 10:42
not quite getting the constraint here. we want cobdate (startDate) after endDate (recordDate) – M06H Apr 08 '21 at 10:44
you need to call `isOlderThanXDays(5, recordDate, cobDate)` – Panagiotis Bougioukos Apr 08 '21 at 10:47
then it should say `if (startDate.isBefore(endDate)) {` ? – M06H Apr 08 '21 at 10:49
@M06H I just throw an exception when the startDate is after the endDate. Just to be sure that the method will be called with a `startDate` that will be before `endDate` – Panagiotis Bougioukos Apr 08 '21 at 10:52
`startDate` must be the earlier chronological date than `endDate` – Panagiotis Bougioukos Apr 08 '21 at 10:54

Check if date is older than x days (business days only)

1 Answers1