timepiece/node_modules/date-fns/differenceInCalendarDays.js

57 lines
2.0 KiB
JavaScript

"use strict";
exports.differenceInCalendarDays = differenceInCalendarDays;
var _index = require("./constants.js");
var _index2 = require("./startOfDay.js");
var _index3 = require("./_lib/getTimezoneOffsetInMilliseconds.js");
/**
* @name differenceInCalendarDays
* @category Day Helpers
* @summary Get the number of calendar days between the given dates.
*
* @description
* Get the number of calendar days between the given dates. This means that the times are removed
* from the dates and then the difference in days is calculated.
*
* @typeParam DateType - The `Date` type, the function operates on. Gets inferred from passed arguments. Allows to use extensions like [`UTCDate`](https://github.com/date-fns/utc).
*
* @param dateLeft - The later date
* @param dateRight - The earlier date
*
* @returns The number of calendar days
*
* @example
* // How many calendar days are between
* // 2 July 2011 23:00:00 and 2 July 2012 00:00:00?
* const result = differenceInCalendarDays(
* new Date(2012, 6, 2, 0, 0),
* new Date(2011, 6, 2, 23, 0)
* )
* //=> 366
* // How many calendar days are between
* // 2 July 2011 23:59:00 and 3 July 2011 00:01:00?
* const result = differenceInCalendarDays(
* new Date(2011, 6, 3, 0, 1),
* new Date(2011, 6, 2, 23, 59)
* )
* //=> 1
*/
function differenceInCalendarDays(dateLeft, dateRight) {
const startOfDayLeft = (0, _index2.startOfDay)(dateLeft);
const startOfDayRight = (0, _index2.startOfDay)(dateRight);
const timestampLeft =
+startOfDayLeft -
(0, _index3.getTimezoneOffsetInMilliseconds)(startOfDayLeft);
const timestampRight =
+startOfDayRight -
(0, _index3.getTimezoneOffsetInMilliseconds)(startOfDayRight);
// Round the number of days to the nearest integer because the number of
// milliseconds in a day is not constant (e.g. it's different in the week of
// the daylight saving time clock shift).
return Math.round(
(timestampLeft - timestampRight) / _index.millisecondsInDay,
);
}