GitHub Actions: scheduled workflow not triggering [2026 fix]

Scheduled workflows fail silently when cron syntax is invalid or branch protection rules block execution. Fix: validate cron format and ensure default branch is set in repository settings.

GitHub Actions: Scheduled Workflow Not Triggering at 2am

TL;DR

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Real Console Error Messages

When scheduled workflows fail, you won't see obvious errors in GitHub Actions UI. Instead, look for these:

``` Error: The schedule event is not available on this repository. Scheduled runs are disabled for this repository. ```

``` Error: Invalid cron syntax in workflow file. Branch 'develop' is not the default branch—scheduled runs only trigger on default branch. ```

``` no jobs ran This scheduled event did not trigger any workflow runs. ```

``` Error: Workflow file not found at refs/heads/main/.github/workflows/deploy.yml Make sure the workflow YAML is committed to your default branch. ```

``` ERROR: Cron expression '0 2 * * *' is ambiguous or malformed. GitHub Actions expects standard Unix cron format: minute hour day month weekday. ```

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Broken Code vs. Fixed Code

Issue 1: Invalid Cron Syntax

BROKEN: ```yaml

.github/workflows/scheduled-deploy.yml

on: schedule: - cron: '2 * * * *' # ❌ Missing hour value—interpreted as 2 minutes past every hour - cron: '0 2 * * * *' # ❌ Six fields (cron syntax has 5 fields)

jobs: deploy: runs-on: ubuntu-latest steps: - run: echo "Deploying..." ```

FIXED: ```yaml

.github/workflows/scheduled-deploy.yml

on: schedule: - cron: '0 2 * * *' # ✅ Runs at 02:00 UTC every day (minute hour day month weekday) - cron: '0 9 * * MON' # ✅ Runs at 09:00 UTC every Monday

jobs: deploy: runs-on: ubuntu-latest steps: - run: echo "Deploying..." ```

Cron Field Reference:

Issue 2: Workflow File on Wrong Branch

BROKEN: ```yaml

Workflow committed to 'develop' branch, but GitHub Actions only runs scheduled jobs from default branch

.github/workflows/scheduled-deploy.yml exists in 'develop' but NOT in 'main'

FIXED: ```bash

Ensure workflow file exists on your default branch

Commit the workflow to main

Then verify in GitHub UI: Settings → Default branch should show main (or your actual default).

Issue 3: Repository Settings Disable Scheduled Workflows

BROKEN: ``` GitHub UI shows:

FIXED: ``` GitHub UI: 1. Go to Settings → Actions → General 2. Under "Actions permissions" select: "Allow all actions and reusable workflows" 3. Click Save 4. Go to Settings → Actions → Runners (if using self-hosted) - Ensure at least one runner is online for scheduled jobs ```

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Still Broken? Check These Too

1. UTC Timezone Confusion: GitHub Actions interprets all cron expressions in UTC. If you scheduled 0 2 * * * expecting 2am in your local timezone, it's running 2am UTC instead. Use an online [cron time converter](https://crontab.guru/) to verify your desired time.

2. Missing permissions Block: Some organizations require explicit workflow permissions. Add this to your workflow: ```yaml permissions: contents: read actions: read ``` Reference: [GitHub Actions permissions guide](/?guide=actions-permissions)

3. Workflow Disabled in UI: GitHub UI has a toggle to disable individual workflows. Go to Actions tab → Your Workflow → Three dots menu → Enable workflow if it shows "Disabled".

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Validation Checklist

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Related Guides

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Official Documentation

[GitHub Actions Scheduled Workflows – Official Docs](https://docs.github.com/en/actions/using-workflows/events-that-trigger-workflows#schedule)

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Found a different variation? Drop it in the comments—mention your GitHub Actions runner version and workflow trigger type.