CODEWITHSUNDEEP
javajodatime
zimZille
zimZille

Reputation: 267

JodaTime version1.2 Calculate days

I need to figure out how to calculate how many days there are between 2 dates using joda time 1.2 (no I can not use a newer version). So the Days class doesn't exist yet.

I can do this for the weeks and days

(period.getWeeks()*7 + period.getDays());

But when it comes to months they all have a different number of days in them so I can't do period.getMonths()*30.

edit: I can also do

(today.getDayOfYear() - oldDate.getDayOfYear());

but then there's the problem when the dates are in different years

Thanks

Upvotes: 0

Views: 1041

Answers (1)

Brent Worden
Brent Worden

Reputation: 10974

Take a look at the Joda Time source code. The daysBetween method of Days is defined as:

public static Days daysBetween(ReadableInstant start, ReadableInstant end) {
    int amount = BaseSingleFieldPeriod.between(start, end, DurationFieldType.days());
    return Days.days(amount);
}

BaseSingleFieldPeriod, like Days, is not available in Joda Time 1.2 but, looking at its source classes available in 1.2 start to appear:

protected static int between(ReadableInstant start, ReadableInstant end, DurationFieldType field) {
    if (start == null || end == null) {
        throw new IllegalArgumentException("ReadableInstant objects must not be null");
    }
    Chronology chrono = DateTimeUtils.getInstantChronology(start);
    int amount = field.getField(chrono).getDifference(end.getMillis(), start.getMillis());
    return amount;
}

All of those classes and methods are available in Joda Time 1.2 so computing days between two instances would be something like:

public static int daysBetween(ReadableInstant oldDate, ReadableInstant today) {
    Chronology chrono = DateTimeUtils.getInstantChronology(oldDate);
    int amount = DurationFieldType.days().getField(chrono).getDifference(today.getMillis(), oldDate.getMillis());
    return amount;
}

Upvotes: 1

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