pub fn parse_since_cutoff(input: &str) -> Result<DateTime<Utc>>Expand description
Parse a --since-style value. Accepts either a relative duration
(7d, 24h, 30m, 1w, 90s) or an ISO-8601 absolute timestamp
(2026-04-01, 2026-04-01T12:00:00Z). Returns the resulting cutoff
instant (now - duration, or the ISO value itself).