Twice a year, on two predictable Sundays, some scheduled jobs skip and others fire twice. Diagnose without waiting for autumn.

Wall-clock schedules meet daylight-saving transitions: spring forward deletes an hour of cron targets, fall back repeats one. Schedule in UTC, add idempotency keys, rehearse in staging.

Grounded in researched DevOps, SRE and platform engineering interview loops, written to a senior-engineer editorial bar, and never padded to hit a word count.