My Dates Are Off By One

The failure these share

Every one produces a valid date. That is what makes them survive review and reach a billing run.

• Cron Schedule Semantics — on the spring-forward day a 02:30 job never runs, and most schedulers skip it silently.
• Recurrence Anchor Integrity — every date library gets ONE occurrence right; the drift appears across a SERIES, as a billing date walking off its anchor.
• Timezone Bucket Aggregator — daily metrics computed in UTC are wrong for a whole timezone, and DST days do not have 24 hours.
• SheetJS Cell Type Verdict — a date reads back as `46085`, and the fix buys you a timezone shift instead.
• Retry-After Verdict — a plausible wrong wait: hammer a server that asked for hours, or sleep through the window.
• Chrono Ambiguity Flag — the ambiguity a natural-language date parser resolves silently, rather than reporting.

Why buy them together

They sit on one path: parse, store, schedule, aggregate. A guard at one stage does not help when the drift entered at another — and a date that is wrong by one day is right often enough to pass every test written on a Tuesday.

Each ships with its own tests and is sold separately. This is the set, below the sum.