presto-main/src/main/java/io/prestosql/operator/scalar/DateTimeFunctions.java/DateTimeFunctions/monthFromDate
class DateTimeFunctions:    @Description("month of the year of the given date")
    @ScalarFunction("month")
    @SqlType(StandardTypes.BIGINT)
    public static long monthFromDate(@SqlType(StandardTypes.DATE) long date)
    {
        return MONTH_OF_YEAR.get(DAYS.toMillis(date));
    }