sugar/common/internal/callDateSet.js

A Javascript utility library for working with native objects.

'use strict';

var _utc = require('../var/_utc'),
    callDateGet = require('./callDateGet');

function callDateSet(d, method, value, safe) {
  // "Safe" denotes not setting the date if the value is the same as what is
  // currently set. In theory this should be a noop, however it will cause
  // timezone shifts when in the middle of a DST fallback. This is unavoidable
  // as the notation itself is ambiguous (i.e. there are two "1:00ams" on
  // November 1st, 2015 in northern hemisphere timezones that follow DST),
  // however when advancing or rewinding dates this can throw off calculations
  // so avoiding this unintentional shifting on an opt-in basis.
  if (safe && value === callDateGet(d, method, value)) {
    return;
  }
  d['set' + (_utc(d) ? 'UTC' : '') + method](value);
}

module.exports = callDateSet;