GitHub Actions scheduled workflows not triggering despite active cron configuration

[Caramelix1]

🏷️ Discussion Type

Bug

💬 Feature/Topic Area

Schedule & Cron Jobs

Discussion Details

Bug: Scheduled GitHub Actions workflows are not triggering reliably

Hello GitHub Team,

I am experiencing an issue with scheduled workflows in my private repository.

Repository: Caramelix1/atlas-ai-trading (private)

Workflow: .github/workflows/scan.yml

Default branch: main

Workflow status: Active

Current cron configuration:

schedule:
  - cron: "11,26,41,56 * * * *"

Observed behavior

On October 30, 2026:

• 22 workflow runs were recorded, but only 2 were triggered by schedule.
• The last successful scheduled run was at 02:29:40 (UTC+3).
• The next scheduled run was created at 05:49:02, started 46 minutes and 25 seconds later, and was cancelled before the main scanning step.
• The cron configuration was updated on the default branch at 12:23:08 (UTC+3).
• No new scheduled runs appeared at 12:26, 12:41, 12:56, or 13:11 (UTC+3).
• Manual workflow_dispatch runs work successfully.

Cron update commit: ee1715a1ccca78fd62c17924096d43d34e313481

Expected behavior

The workflow should be triggered approximately every 15 minutes according to its cron schedule.

Actual behavior

Scheduled events are missing for extended periods, even though the workflow is active and the cron configuration is valid.

Questions

Could this be a GitHub Actions scheduler issue affecting this repository?

Are there any repository-level restrictions or scheduling conditions that could explain the missing events?

Thank you for your assistance.

[github-actions[bot]]

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[miguelsalva]

Your cron is fine, and you're already avoiding the top of the hour, which is the usual advice.

What jumps out is that one run was created at 05:49 and only started 46 min later. That looks like the scheduler being backed up, not anything in your repo. There are other reports from Oct 29–30 describing the same thing (#211637, #211632), and GitHub's docs are pretty upfront that scheduled runs can be delayed or dropped under load.

Two things I'd try:

• Disable/enable the workflow from the Actions tab. That sometimes re-registers the schedule after a cron change doesn't.
• If you need every 15 min reliably (a trading scanner probably does), trigger it externally through the workflow_dispatch API. Scheduled workflows on GitHub just aren't built for tight timing.

If it's still dead after re-enabling, I'd open a ticket with the run IDs, since only GitHub staff can see what's happening on the scheduler side.

[christoferpedrosanchezzuzunaga-eng]

Hey @Caramelix1,

Running a cron at 15-minute intervals (11,26,41,56 * * * *) on GitHub Actions will inevitably skip runs. Actions schedules are best-effort; if a runner isn't immediately free or if the previous run overlaps even slightly, the scheduler simply drops the tick rather than queuing it.

For trading bots where missing a scan means missing market signals:

1. Actions isn't really designed for sub-hour recurring cron reliability.
2. A better approach is to keep the bot alive on a lightweight VPS or container, or trigger workflow_dispatch externally via a dedicated webhook.
3. If staying on Actions is mandatory, shifting the cron to off-peak minutes (avoiding numbers ending in 0, 5, or 15) slightly improves reliability, but dropped runs will still happen under platform load.

[christoferpedrosanchezzuzunaga-eng]

Hey @Caramelix1,

Running a cron at 15-minute intervals (11,26,41,56 * * * *) on GitHub Actions will inevitably skip runs. Actions schedules are best-effort; if a runner isn't immediately free or if the previous run overlaps even slightly, the scheduler simply drops the tick rather than queuing it.

For trading bots where missing a scan means missing market signals:

1. Actions isn't really designed for sub-hour recurring cron reliability.
2. A better approach is to keep the bot alive on a lightweight VPS or container, or trigger workflow_dispatch externally via a dedicated webhook.
3. If staying on Actions is mandatory, shifting the cron to off-peak minutes (avoiding numbers ending in 0, 5, or 15) slightly improves reliability, but dropped runs will still happen under platform load.