Function isLeapYear

codebase/sources/dhtmlxscheduler.js:15800–15802

(year)

  var ORDINAL_BASE = datetime(1970, 1, 1);
  var PY_WEEKDAYS = [6, 0, 1, 2, 3, 4, 5];
  var isLeapYear = function(year) {
    return year % 4 === 0 && year % 100 !== 0 || year % 400 === 0;
  };
  var isDate = function(value) {
    return value instanceof Date;
  };