Component will receive date, locale and localeUtils props
function YearMonthForm({ date, localeUtils, onChange, fromMonth, toMonth }) {
    const months = localeUtils.getMonths();

    const years = [];
    for (let i = fromMonth.getFullYear(); i <= toMonth.getFullYear(); i += 1) {
        years.push(i);
    }

    const handleChange = function handleChange(e) {
        const { year, month } = e.target.form;
        onChange(new Date(year.value, month.value));
    };

    return (
        <form className="DayPicker-Caption">
            <select name="month" onChange={handleChange} value={date.getMonth()}>
                {months.map((month, i) => <option key={i} value={i}>{month}</option>)}
            </select>
            <select name="year" onChange={handleChange} value={date.getFullYear()}>
                {years.map((year, i) =>
                    <option key={i} value={year}>
                        {year}
                    </option>
                )}
            </select>
        </form>
    );
}