Macro holiday::holiday_const

macro_rules! holiday_const {
    ($(#[$attr:meta])* $var:ident, $name:expr, $month:expr, $day:expr) => { ... };
    ($(#[$attr:meta])* $var:ident, $name:expr, $nth:expr, $weekday:expr, $month:expr) => { ... };
}

Macro to create a pub const Holiday