Forward-statement horizon in days for a given article slug. Returns 0
for unknown slugs and for purely retrospective horizons (week-in-review,
month-in-review, etc.).
Parameters
slug: string
article-type slug
Returns number
horizon length in days, bounded at 1825 (≈ 5 years) by the registry
Forward-statement horizon in days for a given article slug. Returns 0 for unknown slugs and for purely retrospective horizons (week-in-review, month-in-review, etc.).