'use strict'; var GetIntrinsic = require('get-intrinsic'); var $EvalError = GetIntrinsic('%EvalError%'); var DaysInYear = require('./DaysInYear'); var YearFromTime = require('./YearFromTime'); // https://ecma-international.org/ecma-262/5.1/#sec-15.9.1.3 module.exports = function InLeapYear(t) { var days = DaysInYear(YearFromTime(t)); if (days === 365) { return 0; } if (days === 366) { return 1; } throw new $EvalError('Assertion failed: there are not 365 or 366 days in a year, got: ' + days); };