GitHub Actions Schedule (cron) — 2026 Guide with Timezone & Reliability Fixes

2026-07-17 · By Avinash K

GitHub Actions' schedule trigger is the simplest way to run nightly regression, security scans, or dependency updates - but it has three quirks that bite every team: UTC-only, silent 60-day pause, and no built-in jitter. Here's how to use it well.

name: Nightly regression
on:
  schedule:
    - cron: '30 2 * * *'   # 02:30 UTC every day
  workflow_dispatch:        # allow manual runs too
jobs:
  test:
    runs-on: ubuntu-latest
    steps:
      - uses: actions/checkout@v4
      - run: npm ci
      - run: npx playwright install --with-deps
      - run: npx playwright test

GitHub Actions ignores your repository, organisation, and runner timezone. Cron always fires in UTC. Convert first:

India 08:00 IST  -> 02:30 UTC   ->  cron: '30 2 * * *'
US-East 09:00 EST -> 14:00 UTC  ->  cron: '0 14 * * *'
Europe 09:00 CET -> 08:00 UTC   ->  cron: '0 8 * * *'

Daylight saving is on you - a 09:00 EST job becomes 09:00 EDT (one hour earlier UTC) in summer. Either accept the drift or pick UTC directly.

If nobody pushes commits, opens issues, or triggers workflows for 60 days, GitHub disables scheduled workflows automatically. To keep a low-activity repo alive, add a weekly no-op push or a self-ping:

- name: Keepalive
  uses: gautamkrishnar/keepalive-workflow@v2

At exactly 0 * * * * GitHub's queue spikes and your job can be delayed by 5-20 minutes. Spread your schedules to odd minutes:

# Bad - everyone picks this
- cron: '0 * * * *'

# Good - you're one of few on minute 17
- cron: '17 * * * *'

Every hour on the :17                 17 * * * *
Every 30 min, business hours (UTC)    */30 8-18 * * 1-5
Nightly regression at 02:30 UTC       30 2 * * *
Weekly Monday 06:00 UTC report        0 6 * * 1
First of month, midnight UTC          0 0 1 * *
Twice daily 08:00 and 20:00 UTC       0 8,20 * * *
Every 6 hours                         0 */6 * * *
Weekdays only, 09:15 UTC              15 9 * * 1-5
Weekend only, 07:00 UTC               0 7 * * 6,0
Every 15 min                          */15 * * * *
Quarterly (Jan/Apr/Jul/Oct 1st)       0 0 1 1,4,7,10 *
Once a year - Jan 1st, 00:00 UTC     0 0 1 1 *

Getting the UTC conversion wrong is the #1 source of "why didn't my nightly run?" tickets. Paste your expression into the Cron Expression Builder & Tester, switch the timezone to UTC, and confirm the next 10 run times before you commit the workflow. It also has a one-click "GitHub Actions" export that emits the full on: schedule: block.