Quarter as an interval in Simile Timeline.

quarter-interval.js

/*
 * This allows you to use a Quarter as an interval in the Simile Timeline.
 * See http://andrew-jones.com/2009/12/01/using-a-quarter-interval-with-the-simile-timeline/ for info.
 * It has been tested with version 2.3.0 (March 6, 2009). Unlikely to work with other versions.
 * For more information on the timeline, see http://www.simile-widgets.org/wiki/Timeline
 */

SimileAjax.DateTime.QUARTER = 11;

(function() {
    var d = SimileAjax.DateTime;
    var a = d.gregorianUnitLengths;
    
    a[d.QUARTER]      = a[d.MONTH] * 3;
})();

/**
 * Rounds date objects down to the nearest interval or multiple of an interval.
 * This method modifies the given date object, converting it to the given
 * timezone if specified.
 * 
 * @param {Date} date the date object to round
 * @param {Number} intervalUnit a constant, integer index specifying an 
 *   interval, e.g. SimileAjax.DateTime.HOUR
 * @param {Number} timeZone a timezone shift, given in hours
 * @param {Number} multiple a multiple of the interval to round by
 * @param {Number} firstDayOfWeek an integer specifying the first day of the
 *   week, 0 corresponds to Sunday, 1 to Monday, etc.
 */
SimileAjax.DateTime.roundDownToInterval = function(date, intervalUnit, timeZone, multiple, firstDayOfWeek) {
    var timeShift = timeZone * 
        SimileAjax.DateTime.gregorianUnitLengths[SimileAjax.DateTime.HOUR];
        
    var date2 = new Date(date.getTime() + timeShift);
    var clearInDay = function(d) {
        d.setUTCMilliseconds(0);
        d.setUTCSeconds(0);
        d.setUTCMinutes(0);
        d.setUTCHours(0);
    };
    var clearInYear = function(d) {
        clearInDay(d);
        d.setUTCDate(1);
        d.setUTCMonth(0);
    };
    
    switch(intervalUnit) {
    case SimileAjax.DateTime.MILLISECOND:
        var x = date2.getUTCMilliseconds();
        date2.setUTCMilliseconds(x - (x % multiple));
        break;
    case SimileAjax.DateTime.SECOND:
        date2.setUTCMilliseconds(0);
        
        var x = date2.getUTCSeconds();
        date2.setUTCSeconds(x - (x % multiple));
        break;
    case SimileAjax.DateTime.MINUTE:
        date2.setUTCMilliseconds(0);
        date2.setUTCSeconds(0);
        
        var x = date2.getUTCMinutes();
        date2.setTime(date2.getTime() - 
            (x % multiple) * SimileAjax.DateTime.gregorianUnitLengths[SimileAjax.DateTime.MINUTE]);
        break;
    case SimileAjax.DateTime.HOUR:
        date2.setUTCMilliseconds(0);
        date2.setUTCSeconds(0);
        date2.setUTCMinutes(0);
        
        var x = date2.getUTCHours();
        date2.setUTCHours(x - (x % multiple));
        break;
    case SimileAjax.DateTime.DAY:
        clearInDay(date2);
        break;
    case SimileAjax.DateTime.WEEK:
        clearInDay(date2);
        var d = (date2.getUTCDay() + 7 - firstDayOfWeek) % 7;
        date2.setTime(date2.getTime() - 
            d * SimileAjax.DateTime.gregorianUnitLengths[SimileAjax.DateTime.DAY]);
        break;
    case SimileAjax.DateTime.MONTH:
        clearInDay(date2);
        date2.setUTCDate(1);
        
        var x = date2.getUTCMonth();
        date2.setUTCMonth(x - (x % multiple));
        break;
    case SimileAjax.DateTime.QUARTER: // added this
        clearInDay(date2);
        date2.setUTCDate(1);
        
        // x is the numeric month
        // need to work out the start of this quarter
        var x = date2.getUTCMonth();
        
        if( x <= 2 ){
            x = 0;
        } else if( x >= 3 && x <= 5 ){
            x = 3;
        } else if( x >= 6 && x <= 8 ){
            x = 6;
        } else {
            x = 9;
        }
        
        date2.setUTCMonth(x - (x % multiple));
        break;
    case SimileAjax.DateTime.YEAR:
        clearInYear(date2);
        
        var x = date2.getUTCFullYear();
        date2.setUTCFullYear(x - (x % multiple));
        break;
    case SimileAjax.DateTime.DECADE:
        clearInYear(date2);
        date2.setUTCFullYear(Math.floor(date2.getUTCFullYear() / 10) * 10);
        break;
    case SimileAjax.DateTime.CENTURY:
        clearInYear(date2);
        date2.setUTCFullYear(Math.floor(date2.getUTCFullYear() / 100) * 100);
        break;
    case SimileAjax.DateTime.MILLENNIUM:
        clearInYear(date2);
        date2.setUTCFullYear(Math.floor(date2.getUTCFullYear() / 1000) * 1000);
        break;
    }
    
    date.setTime(date2.getTime() - timeShift);
};
/**
 * Increments a date object by a specified interval, taking into
 * consideration the timezone.
 *
 * @param {Date} date the date object to increment
 * @param {Number} intervalUnit a constant, integer index specifying an 
 *   interval, e.g. SimileAjax.DateTime.HOUR
 * @param {Number} timeZone the timezone offset in hours
 */
SimileAjax.DateTime.incrementByInterval = function(date, intervalUnit, timeZone) {
    timeZone = (typeof timeZone == 'undefined') ? 0 : timeZone;

    var timeShift = timeZone * 
        SimileAjax.DateTime.gregorianUnitLengths[SimileAjax.DateTime.HOUR];
        
    var date2 = new Date(date.getTime() + timeShift);

    switch(intervalUnit) {
    case SimileAjax.DateTime.MILLISECOND:
        date2.setTime(date2.getTime() + 1)
        break;
    case SimileAjax.DateTime.SECOND:
        date2.setTime(date2.getTime() + 1000);
        break;
    case SimileAjax.DateTime.MINUTE:
        date2.setTime(date2.getTime() + 
            SimileAjax.DateTime.gregorianUnitLengths[SimileAjax.DateTime.MINUTE]);
        break;
    case SimileAjax.DateTime.HOUR:
        date2.setTime(date2.getTime() + 
            SimileAjax.DateTime.gregorianUnitLengths[SimileAjax.DateTime.HOUR]);
        break;
    case SimileAjax.DateTime.DAY:
        date2.setUTCDate(date2.getUTCDate() + 1);
        break;
    case SimileAjax.DateTime.WEEK:
        date2.setUTCDate(date2.getUTCDate() + 7);
        break;
    case SimileAjax.DateTime.MONTH:
        date2.setUTCMonth(date2.getUTCMonth() + 1);
        break;
    case SimileAjax.DateTime.QUARTER: // added this
        date2.setUTCMonth(date2.getUTCMonth() + 3);
        break;
    case SimileAjax.DateTime.YEAR:
        date2.setUTCFullYear(date2.getUTCFullYear() + 1);
        break;
    case SimileAjax.DateTime.DECADE:
        date2.setUTCFullYear(date2.getUTCFullYear() + 10);
        break;
    case SimileAjax.DateTime.CENTURY:
        date2.setUTCFullYear(date2.getUTCFullYear() + 100);
        break;
    case SimileAjax.DateTime.MILLENNIUM:
        date2.setUTCFullYear(date2.getUTCFullYear() + 1000);
        break;
    }

    date.setTime(date2.getTime() - timeShift);
};
Timeline.GregorianDateLabeller.prototype.defaultLabelInterval = function(date, intervalUnit) {
    var text;
    var emphasized = false;
    
    date = SimileAjax.DateTime.removeTimeZoneOffset(date, this._timeZone);
    
    switch(intervalUnit) {
    case SimileAjax.DateTime.MILLISECOND:
        text = date.getUTCMilliseconds();
        break;
    case SimileAjax.DateTime.SECOND:
        text = date.getUTCSeconds();
        break;
    case SimileAjax.DateTime.MINUTE:
        var m = date.getUTCMinutes();
        if (m == 0) {
            text = date.getUTCHours() + ":00";
            emphasized = true;
        } else {
            text = m;
        }
        break;
    case SimileAjax.DateTime.HOUR:
        text = date.getUTCHours() + "hr";
        break;
    case SimileAjax.DateTime.DAY:
        text = Timeline.GregorianDateLabeller.getMonthName(date.getUTCMonth(), this._locale) + " " + date.getUTCDate();
        break;
    case SimileAjax.DateTime.WEEK:
        text = Timeline.GregorianDateLabeller.getMonthName(date.getUTCMonth(), this._locale) + " " + date.getUTCDate();
        break;
    case SimileAjax.DateTime.MONTH:
        var m = date.getUTCMonth();
        if (m != 0) {
            text = Timeline.GregorianDateLabeller.getMonthName(m, this._locale);
            break;
        } // else, fall through
    case SimileAjax.DateTime.QUARTER: // Added this
        var m = date.getUTCMonth();
        
        // which quarter are we in?
        switch( m ){
        case 0:
            text = 'Q1 ' + date.getUTCFullYear();
            break;
        case 3:
            text = 'Q2 ' + date.getUTCFullYear();
            break;
        case 6:
            text = 'Q3 ' + date.getUTCFullYear();
            break;
        case 9:
            text = 'Q4 ' + date.getUTCFullYear();
            break;
        }
        break;
    case SimileAjax.DateTime.YEAR:
    case SimileAjax.DateTime.DECADE:
    case SimileAjax.DateTime.CENTURY:
    case SimileAjax.DateTime.MILLENNIUM:
        var y = date.getUTCFullYear();
        if (y > 0) {
            text = date.getUTCFullYear();
        } else {
            text = (1 - y) + "BC";
        }
        emphasized = 
            (intervalUnit == SimileAjax.DateTime.MONTH) ||
            (intervalUnit == SimileAjax.DateTime.DECADE && y % 100 == 0) || 
            (intervalUnit == SimileAjax.DateTime.CENTURY && y % 1000 == 0);
        break;
    default:
        text = date.toUTCString();
    }
    return { text: text, emphasized: emphasized };
}