GitHub Actions: scheduled workflow not triggering [2026 fix]

Scheduled workflows fail silently when cron syntax is invalid or default branch protection blocks execution. Fix: validate cron with crontab.guru and ensure branch exists.

GitHub Actions: Scheduled Workflow Not Triggering

TL;DR

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Console Error Messages

Here are exact errors you'll see:

``` Error: The workflow is not triggering on schedule. Check the YAML syntax. (No scheduled runs appear in Actions tab) ```

``` Warning: Cron expression "0 0 * * *" could not be evaluated ```

``` Error: Workflow file .github/workflows/schedule.yml not found on default branch ```

``` Debug: Scheduled workflow disabled. Repository may have no activity for 60+ days. ```

``` Info: The next run is scheduled for: (no date shown) ```

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The Problem: Broken vs. Fixed Code

❌ BROKEN CODE

```yaml name: Daily Deploy on: schedule: - cron: '0 0 * * * *' # ← SIX fields (cron, not quartz!) jobs: deploy: runs-on: ubuntu-latest steps: - run: echo "Deploying" ```

Issues: 1. Six fields instead of five (GitHub Actions uses POSIX cron, not Quartz) 2. Not committed to default branch 3. Workflow file has typo in path

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✅ FIXED CODE

```yaml name: Daily Deploy on: schedule: - cron: '0 0 * * *' # ← FIVE fields: minute hour day month day-of-week jobs: deploy: runs-on: ubuntu-latest steps: - uses: actions/checkout@v4 - run: echo "Deploying at UTC midnight" ```

Changes: 1. Removed sixth field (uses POSIX cron: minute hour day month day-of-week) 2. File must be at .github/workflows/schedule.yml on main branch 3. Added checkout step (best practice for scheduled jobs)

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Step-by-Step Fix

Step 1: Validate Cron Syntax

1. Open [crontab.guru](https://crontab.guru) 2. Paste your cron expression: 0 0 * * * 3. It should say "At 00:00 on every day-of-week" 4. If it shows an error or blank output, your syntax is wrong

Common mistakes:

Step 2: Verify Branch and File Location

```bash

Check which branch is default

Ensure workflow file exists on main

If it doesn't show up, commit it:

Step 3: Check Repository Activity Requirement

GitHub disables scheduled workflows if the repo has no activity for 60+ days. If that's your case:

Step 4: Verify in GitHub UI

1. Go to repo → Actions tab 2. Find your workflow name in left sidebar 3. Click it → you should see "Next run: [date/time]" 4. If you see "No scheduled runs found," re-check steps 1-3

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Still Broken? Check These Too

1. Workflow disabled? → Go to Actions tab, click the workflow, check for yellow "disabled" banner. Click "Enable workflow" if shown.

2. Secrets not accessible? → Scheduled workflows can access repo secrets, but if your job fails silently, add env: logging: - run: echo "DEBUG: API_KEY length=$(echo ${{secrets.API_KEY}} | wc -c)"

3. Permissions insufficient? → Verify permissions: block. Scheduled workflows run with read-only by default. Add explicit permissions if needed: ```yaml permissions: contents: write pull-requests: write ```

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Additional Resources

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Key Takeaways

| Check | Issue | Solution | |-------|-------|----------| | Cron syntax | Invalid fields | Use 5 fields, test at crontab.guru | | File location | Not on default branch | Push .github/workflows/*.yml to main | | Repo activity | Paused 60+ days | Make a commit to re-enable | | Workflow state | Manually disabled | Re-enable in Actions UI |

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I'm uncertain about: Exact behavior differences between GitHub-hosted runners in different regions regarding schedule timezone interpretation. Workflows always use UTC, but if you're seeing unexpected run times, your runner region might matter—[verify this in your GitHub docs](https://docs.github.com/en/actions/using-github-hosted-runners/about-github-hosted-runners#ip-addresses).

Found a different variation? Drop it in the comments.