Calculating dates given two dates excluding weekend

Question

I am using Joda time api in a Spring 3.0 project for to calculate dates. Now I have a start and end date and I want to get everyday exept weekend or Saturday or Sunday betwe

Answer 1

I have been using @Josh Maag's logic for almost a year now but recently found that it returns wrong value when endDate happens to fall on a Saturday.

Here is the version I would like to share which considers to subtract days from endDate when it happens to be a Saturday or a Sunday.

public static int getDaysBetweenIgnoreWeekends(org.joda.time.DateTime startDate, org.joda.time.DateTime endDate, boolean ignoreTimeOfDay) {

    // If the start date is equal to the closing date, spent 0 days
    if (startDate.equals(endDate))
        return 0;
    if (ignoreTimeOfDay && startDate.toLocalDate().equals(endDate.toLocalDate()))
        return 0;

    // A number that represents the day for the start date, Monday = 1 , Tuesday = 2 , Wednesday = 3 ...
    int dayOfWeekStartDateNumber = startDate.getDayOfWeek();
    int dayOfWeekEndDateNumber = endDate.getDayOfWeek();

    // If the starting date is Saturday or Sunday , pretend to be Monday
    if (dayOfWeekStartDateNumber == 6 || dayOfWeekStartDateNumber == 7) {
        int DaysToAdd = 8 - dayOfWeekStartDateNumber;
        startDate = startDate.plusDays(DaysToAdd);
        dayOfWeekStartDateNumber = Integer.valueOf(startDate.dayOfWeek().getAsString());
    }

    org.joda.time.DateTime effectiveEndDate = endDate; 

    if (dayOfWeekEndDateNumber == 6 || dayOfWeekEndDateNumber == 7) {
        effectiveEndDate = endDate.minusDays(Math.abs(5 - dayOfWeekEndDateNumber)); 
    }

    // How many days have passed counting weekends
    int days;
    if(ignoreTimeOfDay) {
        days = org.joda.time.Days.daysBetween(startDate.toLocalDate(), effectiveEndDate.toLocalDate()).getDays();
    } else {
        days = org.joda.time.Days.daysBetween(startDate, effectiveEndDate).getDays();
    }

    // How many weeks have passed
    int weeks = days / 7;
    // Excess days left. E.g. one week and three days the excess will be 3

    int excess = days % 7;

    // Excess of days spent for the weekend , then it must be removed two days
    // the final number of days
    if (excess + dayOfWeekStartDateNumber >= 6) {
        // Week count * 5 working days + excess days - the weekend that excess crossed
        return weeks * 5 + excess - 2;
    }
    // Weeks count * 5 working days + excess days
    return weeks * 5 + excess;
}

In the earlier version - following snippet was subtracting an extra day. Subtracting -2 no matter if endDate was a Saturday or Sunday.

if (excess + dayOfWeekStartDateNumber >= 6) {
    // Week count * 5 working days + excess days - the weekend that excess crossed
    return weeks * 5 + excess - 2;
} 

Hope that helps!