Analog of ORACLE function MONTHS_BETWEEN in Java

Question

Does Java have some analog of Oracle\'s function MONTHS_BETWEEN?

Answer 1

The previous answers are not perfect because they do not handle dates such as Feb 31.

Here is my iterative interpretation of MONTHS_BETWEEN in Javascript...

    // Replica of the Oracle function MONTHS_BETWEEN where it calculates based on 31-day months
    var MONTHS_BETWEEN = function(d1, d2) {
        // Don't even try to calculate if it's the same day
        if (d1.getTicks() === d2.getTicks()) return 0;

        var totalDays = 0;
        var earlyDte = (d1 < d2 ? d1 : d2); // Put the earlier date in here
        var laterDate = (d1 > d2 ? d1 : d2); // Put the later date in here
        // We'll need to compare dates using string manipulation because dates such as 
        // February 31 will not parse correctly with the native date object
        var earlyDteStr = [(earlyDte.getMonth() + 1), earlyDte.getDate(), earlyDte.getFullYear()];

        // Go in day-by-day increments, treating every month as having 31 days
        while (earlyDteStr[2] < laterDate.getFullYear() ||
               earlyDteStr[2] == laterDate.getFullYear() && earlyDteStr[0] < (laterDate.getMonth() + 1) ||
               earlyDteStr[2] == laterDate.getFullYear() && earlyDteStr[0] == (laterDate.getMonth() + 1) && earlyDteStr[1] < laterDate.getDate()) {
            if (earlyDteStr[1] + 1 < 32) {
                earlyDteStr[1] += 1; // Increment the day
            } else {
                // If we got to this clause, then we need to carry over a month
                if (earlyDteStr[0] + 1 < 13) {
                    earlyDteStr[0] += 1; // Increment the month
                } else {
                    // If we got to this clause, then we need to carry over a year
                    earlyDteStr[2] += 1; // Increment the year
                    earlyDteStr[0] = 1; // Reset the month
                }
                earlyDteStr[1] = 1; // Reset the day
            }

            totalDays += 1; // Add to our running sum of days for this iteration
        }
        return (totalDays / 31.0);
    };