public static int getDaysBetween(UTCDate start, UTCDate finish) {
        // Convert the dates to the same time
        start = copyDate(start);
        resetTime(start);
        finish = copyDate(finish);
        resetTime(finish);

        double aTime = start.getTime();
        double bTime = finish.getTime();

        long adjust = 60 * 60 * 1000;
        adjust = (bTime > aTime) ? adjust : -adjust;

        return (int) ((bTime - aTime + adjust) / (24 * 60 * 60 * 1000));
    }
Returns the number of days between the two dates. Time is ignored.

@param start starting date
@param finish ending date
@return the different
stroom-core-client-widget/src/main/java/stroom/widget/datepicker/client/CalendarUtil.java