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std/datetime/difference.ts

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// Copyright 2018-2024 the Deno authors. All rights reserved. MIT license.// This module is browser compatible.
import { DAY, HOUR, MINUTE, SECOND, WEEK } from "./constants.ts";
/** * Duration units for {@linkcode DifferenceFormat} and * {@linkcode DifferenceOptions}. */export type Unit = | "milliseconds" | "seconds" | "minutes" | "hours" | "days" | "weeks" | "months" | "quarters" | "years";
/** Return type for {@linkcode difference}. */export type DifferenceFormat = Partial<Record<Unit, number>>;
/** Options for {@linkcode difference}. */export type DifferenceOptions = { units?: Unit[];};
function calculateMonthsDifference(from: Date, to: Date): number { let months = (to.getFullYear() - from.getFullYear()) * 12 + (to.getMonth() - from.getMonth()); if (to.getDate() < from.getDate()) { months--; } return months;}
/** * Calculates the difference of the 2 given dates in the given units. If the units * are omitted, it returns the difference in the all available units. * * @param from Year to calculate difference from. * @param to Year to calculate difference to. * @param options Options such as units to calculate difference in. * * @example Basic usage * ```ts * import { difference } from "https://deno.land/std@$STD_VERSION/datetime/difference.ts"; * * const date0 = new Date("2018-05-14"); * const date1 = new Date("2020-05-13"); * * difference(date0, date1); * // { * // milliseconds: 63072000000, * // seconds: 63072000, * // minutes: 1051200, * // hours: 17520, * // days: 730, * // weeks: 104, * // months: 23, * // quarters: 7, * // years: 1 * // } * ``` * * @example Calculate difference in specific units * ```ts * import { difference } from "https://deno.land/std@$STD_VERSION/datetime/difference.ts"; * * const date0 = new Date("2018-05-14"); * const date1 = new Date("2020-05-13"); * * difference(date0, date1, { units: ["days", "months", "years"] }); * // { days: 730, months: 23, years: 1 } * ``` */export function difference( from: Date, to: Date, options?: DifferenceOptions,): DifferenceFormat { [from, to] = from < to ? [from, to] : [to, from]; const uniqueUnits = options?.units ? [...new Set(options?.units)] : [ "milliseconds", "seconds", "minutes", "hours", "days", "weeks", "months", "quarters", "years", ];
const differenceInMs = Math.abs(from.getTime() - to.getTime());
const differences: DifferenceFormat = {};
for (const uniqueUnit of uniqueUnits) { switch (uniqueUnit) { case "milliseconds": differences.milliseconds = differenceInMs; break; case "seconds": differences.seconds = Math.floor(differenceInMs / SECOND); break; case "minutes": differences.minutes = Math.floor(differenceInMs / MINUTE); break; case "hours": differences.hours = Math.floor(differenceInMs / HOUR); break; case "days": differences.days = Math.floor(differenceInMs / DAY); break; case "weeks": differences.weeks = Math.floor(differenceInMs / WEEK); break; case "months": differences.months = calculateMonthsDifference(from, to); break; case "quarters": differences.quarters = Math.floor( (differences.months !== undefined && differences.months / 3) || calculateMonthsDifference(from, to) / 3, ); break; case "years": differences.years = Math.floor( (differences.months !== undefined && differences.months / 12) || calculateMonthsDifference(from, to) / 12, ); break; } }
return differences;}