date-fns-tz/_lib/tzParseTimezone/index.js

Time zone support for date-fns v2 with the browser Intl API

"use strict";

Object.defineProperty(exports, "__esModule", {
  value: true
});
exports.default = tzParseTimezone;

var _index = _interopRequireDefault(require("../tzTokenizeDate/index.js"));

function _interopRequireDefault(obj) { return obj && obj.__esModule ? obj : { default: obj }; }

var MILLISECONDS_IN_HOUR = 3600000;
var MILLISECONDS_IN_MINUTE = 60000;
var patterns = {
  timezone: /([Z+-].*)$/,
  timezoneZ: /^(Z)$/,
  timezoneHH: /^([+-])(\d{2})$/,
  timezoneHHMM: /^([+-])(\d{2}):?(\d{2})$/,
  timezoneIANA: /(UTC|(?:[a-zA-Z]+\/[a-zA-Z_]+(?:\/[a-zA-Z_]+)?))$/
}; // Parse various time zone offset formats to an offset in milliseconds

function tzParseTimezone(timezoneString, date) {
  var token;
  var absoluteOffset; // Z

  token = patterns.timezoneZ.exec(timezoneString);

  if (token) {
    return 0;
  }

  var hours; // ±hh

  token = patterns.timezoneHH.exec(timezoneString);

  if (token) {
    hours = parseInt(token[2], 10);

    if (!validateTimezone(hours)) {
      return NaN;
    }

    absoluteOffset = hours * MILLISECONDS_IN_HOUR;
    return token[1] === '+' ? -absoluteOffset : absoluteOffset;
  } // ±hh:mm or ±hhmm


  token = patterns.timezoneHHMM.exec(timezoneString);

  if (token) {
    hours = parseInt(token[2], 10);
    var minutes = parseInt(token[3], 10);

    if (!validateTimezone(hours, minutes)) {
      return NaN;
    }

    absoluteOffset = hours * MILLISECONDS_IN_HOUR + minutes * MILLISECONDS_IN_MINUTE;
    return token[1] === '+' ? -absoluteOffset : absoluteOffset;
  } // IANA time zone


  token = patterns.timezoneIANA.exec(timezoneString);

  if (token) {
    date = new Date(date || Date.now());
    date.setMilliseconds(0); // var [fYear, fMonth, fDay, fHour, fMinute, fSecond] = tzTokenizeDate(date, timezoneString)

    var tokens = (0, _index.default)(date, timezoneString);
    var asUTC = Date.UTC(tokens[0], tokens[1] - 1, tokens[2], tokens[3], tokens[4], tokens[5]);
    return -(asUTC - date.getTime());
  }

  return 0;
}

function validateTimezone(hours, minutes) {
  if (minutes != null && (minutes < 0 || minutes > 59)) {
    return false;
  }

  return true;
}

module.exports = exports.default;