- * In the U.S, Jan 1st is normally used based on a Sunday start of week. - * ISO 8601, used widely throughout Europe, uses Jan 4th, based on a Monday start of week. - *
- * @property WEEK_ONE_JAN_DATE - * @static - * @type Number - */ - WEEK_ONE_JAN_DATE : 1, - - /** - * Adds the specified amount of time to the this instance. - * @method add - * @param {Date} date The JavaScript Date object to perform addition on - * @param {String} field The field constant to be used for performing addition. - * @param {Number} amount The number of units (measured in the field constant) to add to the date. - * @return {Date} The resulting Date object - */ - add : function(date, field, amount) { - var d = new Date(date.getTime()); - switch (field) { - case this.MONTH: - var newMonth = date.getMonth() + amount; - var years = 0; - - if (newMonth < 0) { - while (newMonth < 0) { - newMonth += 12; - years -= 1; - } - } else if (newMonth > 11) { - while (newMonth > 11) { - newMonth -= 12; - years += 1; - } - } - - d.setMonth(newMonth); - d.setFullYear(date.getFullYear() + years); - break; - case this.DAY: - this._addDays(d, amount); - // d.setDate(date.getDate() + amount); - break; - case this.YEAR: - d.setFullYear(date.getFullYear() + amount); - break; - case this.WEEK: - this._addDays(d, (amount * 7)); - // d.setDate(date.getDate() + (amount * 7)); - break; - } - return d; - }, - - /** - * Private helper method to account for bug in Safari 2 (webkit < 420) - * when Date.setDate(n) is called with n less than -128 or greater than 127. - *- * Fix approach and original findings are available here: - * http://brianary.blogspot.com/2006/03/safari-date-bug.html - *
- * @method _addDays - * @param {Date} d JavaScript date object - * @param {Number} nDays The number of days to add to the date object (can be negative) - * @private - */ - _addDays : function(d, nDays) { - if (YAHOO.env.ua.webkit && YAHOO.env.ua.webkit < 420) { - if (nDays < 0) { - // Ensure we don't go below -128 (getDate() is always 1 to 31, so we won't go above 127) - for(var min = -128; nDays < min; nDays -= min) { - d.setDate(d.getDate() + min); - } - } else { - // Ensure we don't go above 96 + 31 = 127 - for(var max = 96; nDays > max; nDays -= max) { - d.setDate(d.getDate() + max); - } - } - // nDays should be remainder between -128 and 96 - } - d.setDate(d.getDate() + nDays); - }, - - /** - * Subtracts the specified amount of time from the this instance. - * @method subtract - * @param {Date} date The JavaScript Date object to perform subtraction on - * @param {Number} field The this field constant to be used for performing subtraction. - * @param {Number} amount The number of units (measured in the field constant) to subtract from the date. - * @return {Date} The resulting Date object - */ - subtract : function(date, field, amount) { - return this.add(date, field, (amount*-1)); - }, - - /** - * Determines whether a given date is before another date on the calendar. - * @method before - * @param {Date} date The Date object to compare with the compare argument - * @param {Date} compareTo The Date object to use for the comparison - * @return {Boolean} true if the date occurs before the compared date; false if not. - */ - before : function(date, compareTo) { - var ms = compareTo.getTime(); - if (date.getTime() < ms) { - return true; - } else { - return false; - } - }, - - /** - * Determines whether a given date is after another date on the calendar. - * @method after - * @param {Date} date The Date object to compare with the compare argument - * @param {Date} compareTo The Date object to use for the comparison - * @return {Boolean} true if the date occurs after the compared date; false if not. - */ - after : function(date, compareTo) { - var ms = compareTo.getTime(); - if (date.getTime() > ms) { - return true; - } else { - return false; - } - }, - - /** - * Determines whether a given date is between two other dates on the calendar. - * @method between - * @param {Date} date The date to check for - * @param {Date} dateBegin The start of the range - * @param {Date} dateEnd The end of the range - * @return {Boolean} true if the date occurs between the compared dates; false if not. - */ - between : function(date, dateBegin, dateEnd) { - if (this.after(date, dateBegin) && this.before(date, dateEnd)) { - return true; - } else { - return false; - } - }, - - /** - * Retrieves a JavaScript Date object representing January 1 of any given year. - * @method getJan1 - * @param {Number} calendarYear The calendar year for which to retrieve January 1 - * @return {Date} January 1 of the calendar year specified. - */ - getJan1 : function(calendarYear) { - return this.getDate(calendarYear,0,1); - }, - - /** - * Calculates the number of days the specified date is from January 1 of the specified calendar year. - * Passing January 1 to this function would return an offset value of zero. - * @method getDayOffset - * @param {Date} date The JavaScript date for which to find the offset - * @param {Number} calendarYear The calendar year to use for determining the offset - * @return {Number} The number of days since January 1 of the given year - */ - getDayOffset : function(date, calendarYear) { - var beginYear = this.getJan1(calendarYear); // Find the start of the year. This will be in week 1. - - // Find the number of days the passed in date is away from the calendar year start - var dayOffset = Math.ceil((date.getTime()-beginYear.getTime()) / this.ONE_DAY_MS); - return dayOffset; - }, - - /** - * Calculates the week number for the given date. Can currently support standard - * U.S. week numbers, based on Jan 1st defining the 1st week of the year, and - * ISO8601 week numbers, based on Jan 4th defining the 1st week of the year. - * - * @method getWeekNumber - * @param {Date} date The JavaScript date for which to find the week number - * @param {Number} firstDayOfWeek The index of the first day of the week (0 = Sun, 1 = Mon ... 6 = Sat). - * Defaults to 0 - * @param {Number} janDate The date in the first week of January which defines week one for the year - * Defaults to the value of YAHOO.widget.DateMath.WEEK_ONE_JAN_DATE, which is 1 (Jan 1st). - * For the U.S, this is normally Jan 1st. ISO8601 uses Jan 4th to define the first week of the year. - * - * @return {Number} The number of the week containing the given date. - */ - getWeekNumber : function(date, firstDayOfWeek, janDate) { - - // Setup Defaults - firstDayOfWeek = firstDayOfWeek || 0; - janDate = janDate || this.WEEK_ONE_JAN_DATE; - - var targetDate = this.clearTime(date), - startOfWeek, - endOfWeek; - - if (targetDate.getDay() === firstDayOfWeek) { - startOfWeek = targetDate; - } else { - startOfWeek = this.getFirstDayOfWeek(targetDate, firstDayOfWeek); - } - - var startYear = startOfWeek.getFullYear(); - - // DST shouldn't be a problem here, math is quicker than setDate(); - endOfWeek = new Date(startOfWeek.getTime() + 6*this.ONE_DAY_MS); - - var weekNum; - if (startYear !== endOfWeek.getFullYear() && endOfWeek.getDate() >= janDate) { - // If years don't match, endOfWeek is in Jan. and if the - // week has WEEK_ONE_JAN_DATE in it, it's week one by definition. - weekNum = 1; - } else { - // Get the 1st day of the 1st week, and - // find how many days away we are from it. - var weekOne = this.clearTime(this.getDate(startYear, 0, janDate)), - weekOneDayOne = this.getFirstDayOfWeek(weekOne, firstDayOfWeek); - - // Round days to smoothen out 1 hr DST diff - var daysDiff = Math.round((targetDate.getTime() - weekOneDayOne.getTime())/this.ONE_DAY_MS); - - // Calc. Full Weeks - var rem = daysDiff % 7; - var weeksDiff = (daysDiff - rem)/7; - weekNum = weeksDiff + 1; - } - return weekNum; - }, - - /** - * Get the first day of the week, for the give date. - * @param {Date} dt The date in the week for which the first day is required. - * @param {Number} startOfWeek The index for the first day of the week, 0 = Sun, 1 = Mon ... 6 = Sat (defaults to 0) - * @return {Date} The first day of the week - */ - getFirstDayOfWeek : function (dt, startOfWeek) { - startOfWeek = startOfWeek || 0; - var dayOfWeekIndex = dt.getDay(), - dayOfWeek = (dayOfWeekIndex - startOfWeek + 7) % 7; - - return this.subtract(dt, this.DAY, dayOfWeek); - }, - - /** - * Determines if a given week overlaps two different years. - * @method isYearOverlapWeek - * @param {Date} weekBeginDate The JavaScript Date representing the first day of the week. - * @return {Boolean} true if the date overlaps two different years. - */ - isYearOverlapWeek : function(weekBeginDate) { - var overlaps = false; - var nextWeek = this.add(weekBeginDate, this.DAY, 6); - if (nextWeek.getFullYear() != weekBeginDate.getFullYear()) { - overlaps = true; - } - return overlaps; - }, - - /** - * Determines if a given week overlaps two different months. - * @method isMonthOverlapWeek - * @param {Date} weekBeginDate The JavaScript Date representing the first day of the week. - * @return {Boolean} true if the date overlaps two different months. - */ - isMonthOverlapWeek : function(weekBeginDate) { - var overlaps = false; - var nextWeek = this.add(weekBeginDate, this.DAY, 6); - if (nextWeek.getMonth() != weekBeginDate.getMonth()) { - overlaps = true; - } - return overlaps; - }, - - /** - * Gets the first day of a month containing a given date. - * @method findMonthStart - * @param {Date} date The JavaScript Date used to calculate the month start - * @return {Date} The JavaScript Date representing the first day of the month - */ - findMonthStart : function(date) { - var start = this.getDate(date.getFullYear(), date.getMonth(), 1); - return start; - }, - - /** - * Gets the last day of a month containing a given date. - * @method findMonthEnd - * @param {Date} date The JavaScript Date used to calculate the month end - * @return {Date} The JavaScript Date representing the last day of the month - */ - findMonthEnd : function(date) { - var start = this.findMonthStart(date); - var nextMonth = this.add(start, this.MONTH, 1); - var end = this.subtract(nextMonth, this.DAY, 1); - return end; - }, - - /** - * Clears the time fields from a given date, effectively setting the time to 12 noon. - * @method clearTime - * @param {Date} date The JavaScript Date for which the time fields will be cleared - * @return {Date} The JavaScript Date cleared of all time fields - */ - clearTime : function(date) { - date.setHours(12,0,0,0); - return date; - }, - - /** - * Returns a new JavaScript Date object, representing the given year, month and date. Time fields (hr, min, sec, ms) on the new Date object - * are set to 0. The method allows Date instances to be created with the a year less than 100. "new Date(year, month, date)" implementations - * set the year to 19xx if a year (xx) which is less than 100 is provided. - *- * NOTE:Validation on argument values is not performed. It is the caller's responsibility to ensure - * arguments are valid as per the ECMAScript-262 Date object specification for the new Date(year, month[, date]) constructor. - *
- * @method getDate - * @param {Number} y Year. - * @param {Number} m Month index from 0 (Jan) to 11 (Dec). - * @param {Number} d (optional) Date from 1 to 31. If not provided, defaults to 1. - * @return {Date} The JavaScript date object with year, month, date set as provided. - */ - getDate : function(y, m, d) { - var dt = null; - if (YAHOO.lang.isUndefined(d)) { - d = 1; - } - if (y >= 100) { - dt = new Date(y, m, d); - } else { - dt = new Date(); - dt.setFullYear(y); - dt.setMonth(m); - dt.setDate(d); - dt.setHours(0,0,0,0); - } - return dt; - } -}; -YAHOO.register("datemath", YAHOO.widget.DateMath, {version: "2.8.2r1", build: "7"});