Shabbat Aware Scheduler
Schedule jobs, notifications, and automations around Israeli Shabbat and holidays using Hebcal-accurate candle lighting and Havdalah times.
Overview
Shabbat-aware Scheduler is an agent skill most often used in Build (also Ship, Operate) that integrates Hebcal Shabbat and holiday windows so automations pause and resume at correct candle lighting and Havdalah times.
Install
npx skills add https://github.com/skills-il/localization --skill shabbat-aware-schedulerWhat is this skill?
- Documents Hebcal Shabbat times REST behavior with sourced claim IDs in SKILL metadata
- Default candle lighting 18 minutes before sunset; Jerusalem 40 minutes; Haifa and Zikhron Ya'akov 30 minutes
- Havdalah defaults to Tzeit HaKochavim (sun 8.5° below horizon) with m=42, m=50, m=72 minute alternatives
- References Israeli holiday calendar docs and scripts/check_shabbat.py for enforcement
- Localization-focused skill from skills-il for builders serving Israeli users
- Default candle lighting is 18 minutes before sunset; Jerusalem uses 40 minutes; Haifa and Zikhron Ya'akov use 30 minutes
- Havdalah minute alternatives documented: m=42, m=50, m=72 (Rabbeinu Tam)
Adoption & trust: 1 installs on skills.sh; 18 GitHub stars; 2/3 security scanners passed (skills.sh audits); trending (+100% hot-view momentum).
What problem does it solve?
You ship timers and webhooks globally but lack reliable, location-specific Shabbat start and end times, so jobs run when observant users are offline or unavailable.
Who is it for?
Indie SaaS, community apps, and agent automations targeting Israel with real cron, email, or push schedules tied to the Jewish calendar.
Skip if: Products with no Israeli audience, teams unwilling to maintain Hebcal API dependencies, or flows that need rabbinic authority beyond documented API parameters without local review.
When should I use this skill?
User builds or fixes schedulers, crons, or agents that must respect Israeli Shabbat, candle lighting, Havdalah, or holiday blackout windows.
What do I get? / Deliverables
Your scheduler and agent workflows use documented Hebcal defaults and city offsets, with a check script path to validate windows before production traffic hits forbidden hours.
- Hebcal-backed Shabbat and holiday window logic in app or agent workflows
- Validated blackout checks via documented script and reference calendar notes
Recommended Skills
Journey fit
Spans multiple journey phases - primary shelf plus alternate fits below.
Canonical shelf is Build integrations because the skill centers on wiring Hebcal calendar APIs and check scripts into apps and agents—not on one-off idea research. Integrations reflects external calendar REST usage, location-specific candle-lighting offsets, and Havdalah timing parameters in code and schedulers.
Where it fits
Wire Hebcal Shabbat times REST into your job queue so enqueue respects city-specific candle-lighting minutes.
Run check_shabbat.py against staging cron definitions before launch week to catch emails scheduled inside Shabbat.
Update Havdalah m= parameters after community feedback without redeploying unrelated services.
Shift lifecycle SMS sends to post-Havdalah windows for Tel Aviv versus Jerusalem subscribers.
How it compares
Use instead of naive UTC Friday blocks or static offsets that ignore Jerusalem 40-minute candle lighting and configurable Havdalah modes.
Common Questions / FAQ
Who is shabbat-aware-scheduler for?
Solo builders and small teams localizing automation, CRM sequences, or agent tasks for Israeli users who observe Shabbat and need API-backed times, not guesses.
When should I use shabbat-aware-scheduler?
Use it in Build when integrating Hebcal into your app; in Ship when testing that jobs suppress during candle lighting through Havdalah; and in Operate when adjusting cron or on-call bots after daylight or location rule changes.
Is shabbat-aware-scheduler safe to install?
Review the Security Audits panel on this Prism page and treat Hebcal API calls and any scheduler scripts as network-facing code you audit before production.
SKILL.md
READMESKILL.md - Shabbat Aware Scheduler
{ "schemaVersion": "1.0", "skill": "shabbat-aware-scheduler", "generated_at": "2026-05-20", "claims": [ { "claim_id": "candle-lighting-minutes", "claim": "Hebcal default candle lighting is 18 minutes before sunset; Jerusalem uses 40 minutes, Haifa and Zikhron Ya'akov use 30 minutes.", "source_url": "https://www.hebcal.com/home/197/shabbat-times-rest-api", "raw_snippet": "b=18 - Candle-lighting time minutes before sunset. By default, candle lighting time is 18 minutes before sundown ... variations for specific locations like Jerusalem (40 min) and Haifa (30 min).", "fetched_at": "2026-05-20", "appears_in": ["SKILL.md", "SKILL_HE.md", "references/israeli-holiday-calendar.md", "scripts/check_shabbat.py"] }, { "claim_id": "havdalah-default-tzeit-hakochavim", "claim": "Hebcal default Havdalah with M=on is Tzeit HaKochavim, sun 8.5 degrees below horizon. Fixed-minute alternatives: m=42 medium stars, m=50 small stars, m=72 Rabbeinu Tam.", "source_url": "https://www.hebcal.com/home/4463/candle-lighting-havdalah-fast-times", "raw_snippet": "tzeit hakochavim (when 3 small stars are visible, sun 8.5 below horizon) ... 42 minutes for three medium-sized stars, 50 minutes for three small stars, 72 minutes for Rabbeinu Tam, 0 to suppress.", "fetched_at": "2026-05-20", "appears_in": ["SKILL.md", "SKILL_HE.md", "references/israeli-holiday-calendar.md"] }, { "claim_id": "hebcal-api-rate-limit", "claim": "Hebcal API rate-limits at 90 requests per 10-second window, returning HTTP 429.", "source_url": "https://www.hebcal.com/home/developer-apis", "raw_snippet": "Rate-limiting is used to throttle clients ... You may receive a 429 'Too Many Requests' error if your client makes more than 90 requests in a 10-second window.", "fetched_at": "2026-05-20", "appears_in": ["references/israeli-holiday-calendar.md"] }, { "claim_id": "pesach-2026", "claim": "Pesach 2026 runs April 1 to April 8 (first day April 2, last day April 8) in Israeli observance.", "source_url": "https://www.hebcal.com/holidays/2026?i=on", "raw_snippet": "Pesach - Wed, Apr 1 - Wed, Apr 8", "fetched_at": "2026-05-20", "appears_in": ["SKILL.md", "SKILL_HE.md", "references/israeli-holiday-calendar.md"] }, { "claim_id": "shavuot-2026", "claim": "Shavuot 2026 begins evening Thursday May 21 and ends evening Friday May 22, one-day Yom Tov in Israel.", "source_url": "https://www.hebcal.com/holidays/2026?i=on", "raw_snippet": "Shavuot - Thu, May 21 - Fri, May 22", "fetched_at": "2026-05-20", "appears_in": ["SKILL.md", "SKILL_HE.md", "references/israeli-holiday-calendar.md"] }, { "claim_id": "rosh-hashana-2026", "claim": "Rosh Hashana 2026: Friday September 11 (eve) through Sunday September 13. Combined with adjacent Shabbat this creates a three-day no-work span.", "source_url": "https://www.hebcal.com/holidays/2026?i=on", "raw_snippet": "Rosh Hashana - Fri, Sept 11 - Sun, Sept 13 (multi-day span)", "fetched_at": "2026-05-20", "appears_in": ["SKILL.md", "SKILL_HE.md", "references/israeli-holiday-calendar.md"] }, { "claim_id": "yom-kippur-2026", "claim": "Yom Kippur 2026: evening Sunday September 20 through evening Monday September 21.", "source_url": "https://www.hebcal.com/holidays/2026?i=on", "raw_snippet": "Yom Kippur - Sun, Sept 20 - Mon, Sept 21", "fetched_at": "2026-05-20", "appears_in": ["SKILL.md", "SKILL_HE.md", "references/israeli-holiday-calendar.md"] }, { "claim_id": "sukkot-2026", "claim": "Sukkot 2026 in Israel: Friday September 25 (eve) through Friday October 2. Shemini Atzeret/Simchat Torah on October 2-3 (combined in Israel).", "source_url": "https://www.hebcal.com/holidays/2026?i=on", "raw_snippet": "Sukkot - Fri, Sept 25 - Fri, Oct 2 ... Sh