Why AI Agent Schedulers Need a Clock-Skew Budget to Avoid Timing Failures

AI agent schedulers can malfunction not because of faulty cron expressions, but due to mismatches between wall-clock time, monotonic elapsed time, leases, and process restarts. A reliable scheduler requires an explicit clock contract that uses wall-clock time for human-readable records, monotonic clocks for in-process elapsed-time decisions, and database sequences for cross-process ordering. Developers are advised to define a clock-skew budget — the maximum tolerable uncertainty between the scheduling clock and the dispatch authorization clock — and halt new job dispatching if the observed offset exceeds that threshold. Jobs in an uncertain clock state should be flagged as CLOCK_UNCERTAIN rather than silently absorbed into a larger retry window. Fencing tokens and idempotency keys are recommended to prevent duplicate side effects when workers pause, restart, or operate under ambiguous clock conditions.