Macro zmanim_for_offset 

macro_rules! zmanim_for_offset {
    ($offset_fn:expr, [$($fn_name:ident => $zman_type:ident, $doc:expr),* $(,)?]) => { ... };
    (@method_custom $fn_name:ident, $offset_fn:expr, shaah_zmanis_mga, $doc:expr) => { ... };
    (@method_custom $fn_name:ident, $offset_fn:expr, $zman_type:ident, $doc:expr) => { ... };
}