Function imm_code_of
pub fn imm_code_of(date: NaiveDate) -> Option<String>Expand description
The IMM code ("JUN27") naming date, the inverse of
imm_code_to_dates’s reference-period start.
None where date is not the third Wednesday of its month, or where its
year is outside the 2000–2099 window a two-digit code can spell — the same
window imm_code_to_dates resolves in, so the two are inverse over exactly
the codes that exist.
The code names a month, and a month is a monthly-cycle IMM date; a caller
wanting the quarterly restriction asks is_imm_date with
ImmCycle::Imm3M as well.