@thi.ng/date/api.js

Datetime types, relative dates, math, iterators, composable formatters, locales

const DAYS_IN_MONTH = [31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31];
const DAYS_IN_MONTH_OFFSET = [
  0,
  31,
  59,
  90,
  120,
  151,
  181,
  212,
  243,
  273,
  304,
  334
];
const DAYS_IN_400YEARS = 97 * 366 + 303 * 365;
const SECOND = 1e3;
const MINUTE = 60 * SECOND;
const HOUR = 60 * MINUTE;
const DAY = 24 * HOUR;
const WEEK = 7 * DAY;
const YEAR = DAYS_IN_400YEARS / 400 * DAY;
const MONTH = YEAR / 12;
const PERIODS = {
  y: YEAR,
  M: MONTH,
  d: DAY,
  h: HOUR,
  m: MINUTE,
  s: SECOND,
  t: 1,
  w: WEEK,
  q: 3 * MONTH
};
export {
  DAY,
  DAYS_IN_400YEARS,
  DAYS_IN_MONTH,
  DAYS_IN_MONTH_OFFSET,
  HOUR,
  MINUTE,
  MONTH,
  PERIODS,
  SECOND,
  WEEK,
  YEAR
};