Here you can find the source of isThisYear()
Date.prototype.isThisYear = function() { return new Date().getYear() == this.getYear(); };
window = this; Date.prototype.getYear = function() { return new Date().getFullYear(); }; function Error(message, description) { const e = new Error(message); e.description = description; return e;
var weekdays = exports.weekdays = ["sunday", "monday", "tuesday", "wednesday", "thursday", "friday", "saturday"]; Date.prototype.increaseYear = function(num) { this.setUTCFullYear(this.getUTCFullYear() + num); Date.prototype.increaseMonth = function(num) { var str = this.getUTCFullYear()+"-"+(this.getUTCMonth()+num + 1)+"-"+ this.getUTCDate()+"T"+this.getUTCHours()+":"+this.getUTCMinutes()+":"+ this.getUTCSeconds()+"."+this.getUTCMilliseconds()+"Z"; var date = new Date(str); ...
Date.prototype.subYears = function(value) { var month = this.getMonth(); this.setFullYear(this.getFullYear() - value); if (month < this.getMonth()) { this.setDate(0); return this; };
Date.prototype.toYearEnd = function () { var date = new Date(this); date.setMonth(12); date.setDate(0); return date; };
Date.prototype.toYearStart = function () { var date = new Date(this); date.setMonth(0); date.setDate(1); return date; };
Date.prototype.weekOfYear = function () { var year = this.getFullYear(); var d = new Date(this); d.setHours(0, 0, 0, 0); var yearStart = new Date(year, 0, 1); d.setDate(d.getDate() + yearStart.getDay()); var deltaDay = (d.getTime() - yearStart.getTime()) / 86400000 + 1; var weekNo = Math.ceil(deltaDay / 7); return [year, weekNo]; ...