    /**
     * A type of axis whose units are measured in time values. Use this axis
     * for listing dates that you will want to group or dynamically change.
     * If you just want to display dates as categories then use the
     * Category class for axis instead.
     *
     * For example:
     *
     *     axes: [{
     *         type: 'Time',
     *         position: 'bottom',
     *         fields: 'date',
     *         title: 'Day',
     *         dateFormat: 'M d',
     *
     *         constrain: true,
     *         fromDate: new Date('1/1/11'),
     *         toDate: new Date('1/7/11')
     *     }]
     *
     * In this example we're creating a time axis that has as title *Day*.
     * The field the axis is bound to is `date`.
     * The date format to use to display the text for the axis labels is `M d`
     * which is a three letter month abbreviation followed by the day number.
     * The time axis will show values for dates between `fromDate` and `toDate`.
     * Since `constrain` is set to true all other values for other dates not between
     * the fromDate and toDate will not be displayed.
     *
     */
    Ext.define('Ext.chart.axis.Time', {

        /* Begin Definitions */

        extend: 'Ext.chart.axis.Numeric',

        alternateClassName: 'Ext.chart.TimeAxis',

        type: 'Time',

        alias: 'axis.time',

        uses: ['Ext.data.Store'],

        /* End Definitions */

        /**
         * @cfg {String/Boolean} dateFormat
         * Indicates the format the date will be rendered on.
         * For example: 'M d' will render the dates as 'Jan 30', etc.
         * For a list of possible format strings see {@link Ext.Date Date}
         */
        dateFormat: false,

        /**
         * @cfg {Date} fromDate The starting date for the time axis.
         */
        fromDate: false,

        /**
         * @cfg {Date} toDate The ending date for the time axis.
         */
        toDate: false,

        /**
         * @cfg {Array} step
         * An array with two components: The first is the unit of the step (day, month, year, etc). The second one is a number.
         * If the number is an integer, it represents the number of units for the step ([Ext.Date.DAY, 2] means "Every other day").
         * If the number is a fraction, it represents the number of steps per unit ([Ext.Date.DAY, 1/2] means "Twice a day").
         * If the unit is the month, the steps may be adjusted depending on the month. For instance [Ext.Date.MONTH, 1/3], which means "Three times a month",
         * generates steps on the 1st, the 10th and the 20th of every month regardless of whether a month has 28 days or 31 days. The steps are generated
         * as follows:
         * - [Ext.Date.MONTH, n]: on the current date every 'n' months, maxed to the number of days in the month.
         * - [Ext.Date.MONTH, 1/2]: on the 1st and 15th of every month.
         * - [Ext.Date.MONTH, 1/3]: on the 1st, 10th and 20th of every month.
         * - [Ext.Date.MONTH, 1/4]: on the 1st, 8th, 15th and 22nd of every month.
         *
         * Defaults to: [Ext.Date.DAY, 1].
         */
        step: [Ext.Date.DAY, 1],

        /**
         * @cfg {Boolean} constrain
         * If true, the values of the chart will be rendered only if they belong between the fromDate and toDate.
         * If false, the time axis will adapt to the new values by adding/removing steps.
         */
        constrain: false,

        constructor: function (config) {
            var me = this, label, f, df;
            me.callParent([config]);
            label = me.label || {};
            df = this.dateFormat;
            if (df) {
                if (label.renderer) {
                    f = label.renderer;
                    label.renderer = function(v) {
                        v = f(v);
                        return Ext.Date.format(new Date(f(v)), df);
                    };
                } else {
                    label.renderer = function(v) {
                        return Ext.Date.format(new Date(v >> 0), df);
                    };
                }
            }
        },

        // Before rendering, set current default step count to be number of records.
        processView: function () {
            var me = this;
            if (me.fromDate) {
                me.minimum = +me.fromDate;
            }
            if (me.toDate) {
                me.maximum = +me.toDate;
            }
            if(me.constrain){
                me.doConstrain();
            }
         },

        // @private modifies the store and creates the labels for the axes.
        calcEnds: function() {
            var me = this, range, step = me.step;
            if (step) {
                range = me.getRange();
                range = Ext.draw.Draw.snapEndsByDateAndStep(new Date(range.min), new Date(range.max), Ext.isNumber(step) ? [Date.MILLI, step]: step);
                if (me.minimum) {
                    range.from = me.minimum;
                }
                if (me.maximum) {
                    range.to = me.maximum;
                }
                return range;
            } else {
                return me.callParent(arguments);
            }
        }
     });