Function isLeapYear

Pikaday/pikaday.js:116–120

(year)

    },

    isLeapYear = function(year)
    {
        // solution by Matti Virkkunen: http://stackoverflow.com/a/4881951
        return year % 4 === 0 && year % 100 !== 0 || year % 400 === 0;
    },

    getDaysInMonth = function(year, month)
    {