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Module

std/datetime/day_of_year.ts

Deno standard library
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// Copyright 2018-2024 the Deno authors. All rights reserved. MIT license.// This module is browser compatible.
import { DAY } from "./constants.ts";
/** * Returns the number of the day in the year in the local time zone. * * @example * ```ts * import { dayOfYear } from "https://deno.land/std@$STD_VERSION/datetime/mod.ts"; * * dayOfYear(new Date("2019-03-11T03:24:00")); // output: 70 * ``` * * @return Number of the day in the year in the local time zone */export function dayOfYear(date: Date): number { // Values from 0 to 99 map to the years 1900 to 1999. All other values are the actual year. (https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Date/Date) // Using setFullYear as a workaround
const yearStart = new Date(date);
yearStart.setFullYear(date.getFullYear(), 0, 0); const diff = (date.getTime() - date.getTimezoneOffset() * 60 * 1000) - (yearStart.getTime() - yearStart.getTimezoneOffset() * 60 * 1000);
return Math.floor(diff / DAY);}
/** * Returns the number of the day in the year in UTC time. * * @example * ```ts * import { dayOfYearUtc } from "https://deno.land/std@$STD_VERSION/datetime/mod.ts"; * * dayOfYearUtc(new Date("2019-03-11T03:24:00.000Z")) // output 70 * ``` * * @return Number of the day in the year in UTC time */export function dayOfYearUtc(date: Date): number { // Values from 0 to 99 map to the years 1900 to 1999. All other values are the actual year. (https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Date/Date) // Using setUTCFullYear as a workaround
const yearStart = new Date(date);
yearStart.setUTCFullYear(date.getUTCFullYear(), 0, 0); const diff = date.getTime() - yearStart.getTime();
return Math.floor(diff / DAY);}