Here you can find the source of getDOY()
Date.prototype.getDOY = function(){ var firstOfJan = new Date(this.getFullYear(),0,1); return Math.ceil((this - firstOfJan) / 86400000); }
Date.prototype.dayOfYear = function() { var startdayofyear = new Date(this.getFullYear(),0,1); return Math.ceil((this - startdayofyear) / 86400000);
Date.prototype.dayOfYear = function() { var d = new Date(); var yn = d.getFullYear(); var mn = d.getMonth(); var dn = d.getDate(); var d1 = new Date(yn,0,1,12,0,0); var d2 = new Date(yn,mn,dn,12,0,0); var ddiff = Math.round((d2-d1)/864e5); return ddiff+1; ...
Date.prototype.getDOY = function() { var onejan = new Date(this.getFullYear(),0,1); return Math.ceil((this - onejan) / 86400000);
Date.prototype.getDOY = function() { var dayCount = [0, 31, 59, 90, 120, 151, 181, 212, 243, 273, 304, 334]; var mn = this.getMonth(); var dn = this.getDate(); var dayOfYear = dayCount[mn] + dn; if (mn > 1 && this.isLeapYear()) dayOfYear++; return dayOfYear; };
--- --- Date.prototype.getDOY = function() { var onejan = new Date(this.getFullYear(),0,1); return Math.ceil((this - onejan) / 86400000);
Date.prototype.getDOY = function () { var onejan = new Date(this.getFullYear(), 0, 1); return Math.ceil((this - onejan) / 86400000) + 1; };
Date.prototype.getDayOfYear = function() { const janFirst = new Date(this.getFullYear(), 0, 0); const diff = this - janFirst; const millisPerDay = 86400000; return Math.floor(diff / millisPerDay); };