/*
* JulianDate.js - Represent a date in the Julian calendar
*
* Copyright © 2012-2015, 2018, 2023 JEDLSoft
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
*
* See the License for the specific language governing permissions and
* limitations under the License.
*/
var ilib = require("../index.js");
var SearchUtils = require("./SearchUtils.js");
var MathUtils = require("./MathUtils.js");
var Locale = require("./Locale.js");
var LocaleInfo = require("./LocaleInfo.js");
var TimeZone = require("./TimeZone.js");
var IDate = require("./IDate.js");
var JulianRataDie = require("./JulianRataDie.js");
var JulianCal = require("./JulianCal.js");
/**
* @class
* Construct a new date object for the Julian Calendar. The constructor can be called
* with a parameter object that contains any of the following properties:
*
* <ul>
* <li><i>unixtime<i> - sets the time of this instance according to the given
* unix time. Unix time is the number of milliseconds since midnight on Jan 1, 1970 (Gregorian).
* <li><i>julianday</i> - the Julian Day to set into this date
* <li><i>year</i> - any integer except 0. Years go from -1 (BCE) to 1 (CE), skipping the zero
* year which doesn't exist in the Julian calendar
* <li><i>month</i> - 1 to 12, where 1 means January, 2 means February, etc.
* <li><i>day</i> - 1 to 31
* <li><i>hour</i> - 0 to 23. A formatter is used to display 12 hour clocks, but this representation
* is always done with an unambiguous 24 hour representation
* <li><i>minute</i> - 0 to 59
* <li><i>second</i> - 0 to 59
* <li><i>millisecond<i> - 0 to 999
* <li><i>locale</i> - the TimeZone instance or time zone name as a string
* of this julian date. The date/time is kept in the local time. The time zone
* is used later if this date is formatted according to a different time zone and
* the difference has to be calculated, or when the date format has a time zone
* component in it.
* <li><i>timezone</i> - the time zone of this instance. If the time zone is not
* given, it can be inferred from this locale. For locales that span multiple
* time zones, the one with the largest population is chosen as the one that
* represents the locale.
*
* <li><i>date</i> - use the given intrinsic Javascript date to initialize this one.
* </ul>
*
* NB. The <a href="http://en.wikipedia.org/wiki/Julian_date">Julian Day</a>
* (JulianDay) object is a <i>different</i> object than a
* <a href="http://en.wikipedia.org/wiki/Julian_calendar">date in
* the Julian calendar</a> and the two are not to be confused. The Julian Day
* object represents time as a number of whole and fractional days since the
* beginning of the epoch, whereas a date in the Julian
* calendar is a regular date that signifies year, month, day, etc. using the rules
* of the Julian calendar. The naming of Julian Days and the Julian calendar are
* unfortunately close, and come from history.<p>
*
* If called with another Julian date argument, the date components of the given
* date are copied into the current one.<p>
*
* If the constructor is called with no arguments at all or if none of the
* properties listed above
* from <i>unixtime</i> through <i>millisecond</i> are present, then the date
* components are
* filled in with the current date at the time of instantiation. Note that if
* you do not give the time zone when defaulting to the current time and the
* time zone for all of ilib was not set with <i>ilib.setTimeZone()</i>, then the
* time zone will default to UTC ("Universal Time, Coordinated" or "Greenwich
* Mean Time").<p>
*
*
* @constructor
* @extends IDate
* @param {Object=} params parameters that govern the settings and behaviour of this Julian date
*/
var JulianDate = function(params) {
this.cal = new JulianCal();
params = params || {};
if (params.timezone) {
this.timezone = params.timezone;
}
if (params.locale) {
this.locale = (typeof(params.locale) === 'string') ? new Locale(params.locale) : params.locale;
}
if (!this.timezone) {
if (this.locale) {
new LocaleInfo(this.locale, {
sync: params.sync,
loadParams: params.loadParams,
onLoad: ilib.bind(this, function(li) {
this.li = li;
this.timezone = li.getTimeZone();
this._init(params);
})
});
} else {
this.timezone = "local";
this._init(params);
}
} else {
this._init(params);
}
};
JulianDate.prototype = new IDate({noinstance: true});
JulianDate.prototype.parent = IDate;
JulianDate.prototype.constructor = JulianDate;
/**
* Initialize the date
* @private
*/
JulianDate.prototype._init = function (params) {
if (params.year || params.month || params.day || params.hour ||
params.minute || params.second || params.millisecond ) {
/**
* Year in the Julian calendar.
* @type number
*/
this.year = parseInt(params.year, 10) || 0;
/**
* The month number, ranging from 1 (January) to 12 (December).
* @type number
*/
this.month = parseInt(params.month, 10) || 1;
/**
* The day of the month. This ranges from 1 to 31.
* @type number
*/
this.day = parseInt(params.day, 10) || 1;
/**
* The hour of the day. This can be a number from 0 to 23, as times are
* stored unambiguously in the 24-hour clock.
* @type number
*/
this.hour = parseInt(params.hour, 10) || 0;
/**
* The minute of the hours. Ranges from 0 to 59.
* @type number
*/
this.minute = parseInt(params.minute, 10) || 0;
/**
* The second of the minute. Ranges from 0 to 59.
* @type number
*/
this.second = parseInt(params.second, 10) || 0;
/**
* The millisecond of the second. Ranges from 0 to 999.
* @type number
*/
this.millisecond = parseInt(params.millisecond, 10) || 0;
/**
* The day of the year. Ranges from 1 to 383.
* @type number
*/
this.dayOfYear = parseInt(params.dayOfYear, 10);
if (typeof(params.dst) === 'boolean') {
this.dst = params.dst;
}
this.rd = this.newRd(this);
new TimeZone({
id: this.timezone,
sync: params.sync,
loadParams: params.loadParams,
onLoad: ilib.bind(this, function(tz) {
this.tz = tz;
// add the time zone offset to the rd to convert to UTC
// getOffsetMillis requires that this.year, this.rd, and this.dst
// are set in order to figure out which time zone rules apply and
// what the offset is at that point in the year
this.offset = this.tz._getOffsetMillisWallTime(this) / 86400000;
if (this.offset !== 0) {
this.rd = this.newRd({
rd: this.rd.getRataDie() - this.offset
});
}
this._init2(params);
})
});
} else {
this._init2(params);
}
};
/**
* Finish initializing the date
* @private
*/
JulianDate.prototype._init2 = function (params) {
if (!this.rd) {
this.rd = this.newRd(params);
this._calcDateComponents();
}
if (typeof(params.onLoad) === "function") {
params.onLoad(this);
}
};
/**
* Return a new RD for this date type using the given params.
* @protected
* @param {Object=} params the parameters used to create this rata die instance
* @returns {RataDie} the new RD instance for the given params
*/
JulianDate.prototype.newRd = function (params) {
return new JulianRataDie(params);
};
/**
* Return the year for the given RD
* @private
* @param {number} rd RD to calculate from
* @returns {number} the year for the RD
*/
JulianDate.prototype._calcYear = function(rd) {
var year = Math.floor((4*(Math.floor(rd)-1) + 1464)/1461);
return (year <= 0) ? year - 1 : year;
};
/**
* Calculate date components for the given RD date.
* @private
*/
JulianDate.prototype._calcDateComponents = function () {
var remainder,
cumulative,
rd = this.rd.getRataDie();
this.year = this._calcYear(rd);
if (typeof(this.offset) === "undefined") {
this.year = this._calcYear(rd);
// now offset the RD by the time zone, then recalculate in case we were
// near the year boundary
if (!this.tz) {
this.tz = new TimeZone({id: this.timezone});
}
this.offset = this.tz.getOffsetMillis(this) / 86400000;
}
if (this.offset !== 0) {
rd += this.offset;
this.year = this._calcYear(rd);
}
var jan1 = this.newRd({
year: this.year,
month: 1,
day: 1,
hour: 0,
minute: 0,
second: 0,
millisecond: 0
});
remainder = rd + 1 - jan1.getRataDie();
cumulative = this.cal.isLeapYear(this.year) ?
JulianCal.cumMonthLengthsLeap :
JulianCal.cumMonthLengths;
this.month = SearchUtils.bsearch(Math.floor(remainder), cumulative);
remainder = remainder - cumulative[this.month-1];
this.day = Math.floor(remainder);
remainder -= this.day;
// now convert to milliseconds for the rest of the calculation
remainder = Math.round(remainder * 86400000);
this.hour = Math.floor(remainder/3600000);
remainder -= this.hour * 3600000;
this.minute = Math.floor(remainder/60000);
remainder -= this.minute * 60000;
this.second = Math.floor(remainder/1000);
remainder -= this.second * 1000;
this.millisecond = remainder;
};
/**
* Return the day of the week of this date. The day of the week is encoded
* as number from 0 to 6, with 0=Sunday, 1=Monday, etc., until 6=Saturday.
*
* @return {number} the day of the week
*/
JulianDate.prototype.getDayOfWeek = function() {
var rd = Math.floor(this.rd.getRataDie() + (this.offset || 0));
return MathUtils.mod(rd-2, 7);
};
/**
* Return the name of the calendar that governs this date.
*
* @return {string} a string giving the name of the calendar
*/
JulianDate.prototype.getCalendar = function() {
return "julian";
};
//register with the factory method
IDate._constructors["julian"] = JulianDate;
module.exports = JulianDate;
Source