std/datetime

datetime

Simple helper to help parse date strings into Date, with additional functions.

Usage

The following symbols from unicode LDML are supported:

• yyyy - numeric year.

• yy - 2-digit year.

• M - numeric month.

• MM - 2-digit month.

• d - numeric day.

• dd - 2-digit day.

• H - numeric hour (0-23 hours).

• HH - 2-digit hour (00-23 hours).

• h - numeric hour (1-12 hours).

• hh - 2-digit hour (01-12 hours).

• m - numeric minute.

• mm - 2-digit minute.

• s - numeric second.

• ss - 2-digit second.

• S - 1-digit fractionalSecond.

• SS - 2-digit fractionalSecond.

• SSS - 3-digit fractionalSecond.

• a - dayPeriod, either AM or PM.

• 'foo' - quoted literal.

• ./- - unquoted literal.

Methods

parse

Takes an input string and a formatString to parse to a date.

import { parse } from "https://deno.land/std@$STD_VERSION/datetime/mod.ts";

parse("20-01-2019", "dd-MM-yyyy"); // output : new Date(2019, 0, 20)
parse("2019-01-20", "yyyy-MM-dd"); // output : new Date(2019, 0, 20)
parse("20.01.2019", "dd.MM.yyyy"); // output : new Date(2019, 0, 20)
parse("01-20-2019 16:34", "MM-dd-yyyy HH:mm"); // output : new Date(2019, 0, 20, 16, 34)
parse("01-20-2019 04:34 PM", "MM-dd-yyyy hh:mm a"); // output : new Date(2019, 0, 20, 16, 34)
parse("16:34 01-20-2019", "HH:mm MM-dd-yyyy"); // output : new Date(2019, 0, 20, 16, 34)
parse("01-20-2019 16:34:23.123", "MM-dd-yyyy HH:mm:ss.SSS"); // output : new Date(2019, 0, 20, 16, 34, 23, 123)

format

Takes an input date and a formatString to format to a string.

import { format } from "https://deno.land/std@$STD_VERSION/datetime/mod.ts";

format(new Date(2019, 0, 20), "dd-MM-yyyy"); // output : "20-01-2019"
format(new Date(2019, 0, 20), "yyyy-MM-dd"); // output : "2019-01-20"
format(new Date(2019, 0, 20), "dd.MM.yyyy"); // output : "20.01.2019"
format(new Date(2019, 0, 20, 16, 34), "MM-dd-yyyy HH:mm"); // output : "01-20-2019 16:34"
format(new Date(2019, 0, 20, 16, 34), "MM-dd-yyyy hh:mm a"); // output : "01-20-2019 04:34 PM"
format(new Date(2019, 0, 20, 16, 34), "HH:mm MM-dd-yyyy"); // output : "16:34 01-20-2019"
format(new Date(2019, 0, 20, 16, 34, 23, 123), "MM-dd-yyyy HH:mm:ss.SSS"); // output : "01-20-2019 16:34:23.123"
format(new Date(2019, 0, 20), "'today:' yyyy-MM-dd"); // output : "today: 2019-01-20"

dayOfYear

Returns the number of the day in the year.

import { dayOfYear } from "https://deno.land/std@$STD_VERSION/datetime/mod.ts";

dayOfYear(new Date("2019-03-11T03:24:00")); // output: 70

weekOfYear

Returns the ISO week number of the provided date (1-53).

import { weekOfYear } from "https://deno.land/std@$STD_VERSION/datetime/mod.ts";

weekOfYear(new Date("2020-12-28T03:24:00")); // Returns 53

toIMF

Formats the given date to IMF date time format. (Reference: https://tools.ietf.org/html/rfc7231#section-7.1.1.1 )

import { toIMF } from "https://deno.land/std@$STD_VERSION/datetime/mod.ts";

toIMF(new Date(0)); // => returns "Thu, 01 Jan 1970 00:00:00 GMT"

isLeap

Returns true if the given date or year (in number) is a leap year. Returns false otherwise.

import { isLeap } from "https://deno.land/std@$STD_VERSION/datetime/mod.ts";

isLeap(new Date("1970-01-01")); // => returns false
isLeap(new Date("1972-01-01")); // => returns true
isLeap(new Date("2000-01-01")); // => returns true
isLeap(new Date("2100-01-01")); // => returns false
isLeap(1972); // => returns true

difference

Returns 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.

Available units: "milliseconds", "seconds", "minutes", "hours", "days", "weeks", "months", "quarters", "years"

import { difference } from "https://deno.land/std@$STD_VERSION/datetime/mod.ts";

const date0 = new Date("2018-05-14");
const date1 = new Date("2020-05-13");

difference(date0, date1, { units: ["days", "months", "years"] });
// => returns { days: 730, months: 23, years: 1 }

difference(date0, date1);
// => returns {
//   milliseconds: 63072000000,
//   seconds: 63072000,
//   minutes: 1051200,
//   hours: 17520,
//   days: 730,
//   weeks: 104,
//   months: 23,
//   quarters: 5,
//   years: 1
// }

Constants

SECOND

import { SECOND } from "https://deno.land/std@$STD_VERSION/datetime/mod.ts";

console.log(SECOND); // => 1000

MINUTE

import { MINUTE } from "https://deno.land/std@$STD_VERSION/datetime/mod.ts";

console.log(MINUTE); // => 60000 (60 * 1000)

HOUR

import { HOUR } from "https://deno.land/std@$STD_VERSION/datetime/mod.ts";

console.log(HOUR); // => 3600000 (60 * 60 * 1000)

DAY

import { DAY } from "https://deno.land/std@$STD_VERSION/datetime/mod.ts";

console.log(DAY); // => 86400000 (24 * 60 * 60 * 1000)

WEEK

import { WEEK } from "https://deno.land/std@$STD_VERSION/datetime/mod.ts";

console.log(WEEK); // => 604800000 (7 * 24 * 60 * 60 * 1000)