Your GitHub Actions cron fires less often than you declared: what we measured and how to design for it

We run an automated publishing pipeline entirely on GitHub Actions cron schedules — no server, no queue, just workflows that wake up, do one thing, and commit the result. It mostly works. But there is one behaviour of scheduled workflows that the docs mention in a single quiet sentence and that will silently halve your job frequency if you design around the cron expression instead of around reality: Scheduled workflows do not fire as often as you declare. What we measured We had a feedback-watcher workflow declared at four runs per hour: on : schedule : - cron : ' 7,22,37,52 * * * *' Measured over days, it actually fired one to two times per hour — not four, and not at the declared minutes. Roughly hourly on most days, at inconsistent offsets from the declared slots. We later redeclared it at two runs per hour ( 7,37 * * * * ) — measured result: still one to two runs per hour. The declared frequency changed by 2x; the delivered frequency barely moved. This is not an outage and not a misconfiguration. GitHub's own documentation says the schedule event can be delayed during periods of high load , and that high load times include the start of every hour — which is precisely where naive cron expressions cluster — and adds: "If the load is sufficiently high enough, some queued jobs may be dropped." What the docs understate is the magnitude: in our observation, on a private repo, "delayed" in practice meant "throttled to a fraction of the declared rate, indefinitely." What this breaks The failure mode is subtle because nothing goes red. Every run that happens succeeds. The runs that don't happen leave no trace — no log, no failure email, nothing. You only notice if something downstream depends on the frequency: We had promised a "reply within 15 minutes" SLA on incoming feedback, initially backed by the 4x/hour schedule. The schedule couldn't hold it, so for a while we ran a local 15-minute scheduler as the primary path and kept the workflow as fallback. When we later rel