Hebcal API
Agent-ready OpenAPI document · curated by JenticProductivityCalendar Schedulingnone6 EndpointsREST
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For Agents
Compute Jewish holiday calendars, Shabbat times, zmanim, Hebrew date conversions, and yahrzeit dates across 6 unauthenticated endpoints.
Use for: Get the Jewish holidays falling in 2026 for New York, Find this week's Shabbat candle-lighting and havdalah times in Tel Aviv, Calculate today's zmanim for a given latitude and longitude, Convert 15 Nisan 5786 to a Gregorian date
Not supported: Does not write to user calendars, send notifications, or accept event submissions - use for read-only Jewish calendar, zmanim, and date-conversion lookups only.
Jentic publishes the only available OpenAPI specification for Hebcal API, keeping it validated and agent-ready. The Hebcal API is a Jewish calendar service that returns holiday calendars, Shabbat candle-lighting and havdalah times, halachic times (zmanim), Hebrew/Gregorian date conversion, yahrzeit and anniversary calculations, and Torah leyning data. All endpoints are public read-only GETs requiring no authentication, and responses are JSON keyed off location and date parameters. The service does not write to user calendars or accept event submissions.
Install Jentic One Beta
Connect the Hebcal API to your agent
Jentic One is a self-hosted execution layer for AI agents. It lets your agent call the Hebcal API, or any other public or private API you need. You set the rules, the agent never sees your credentials, and every call is logged.
Two steps, two machines. Install the instance in a safe environment, then register your agent from wherever it runs.
1
Step 1: Jentic One Host machine
# On the machine that will host your Jentic One instance:
curl -fsSL "https://jentic.com/install.sh?src=apis&api=%2Fapis%2Fhebcal.com%2Fhebcal" | sh2
Step 2: Agent machine
# On the machine where your agent runs (keep this separate from the instance):
curl -fsSL "https://jentic.com/install.sh?src=apis&api=%2Fapis%2Fhebcal.com%2Fhebcal" | sh
jentic register # connects your agent to your Jentic One instanceJentic One is in public beta. The setup above keeps your agent separate from the instance, which is what you want before using real credentials: an agent running as the same OS user as Jentic One can read its stored keys directly. Just evaluating? A single local install is fine to start. See the secure deployment guide for the tiers.
Capabilities
What an agent can do with Hebcal API.
Generate a Jewish holiday calendar for a given year and location via /hebcal
Look up Shabbat candle-lighting and havdalah times for a city or coordinates via /shabbat
Calculate halachic times (zmanim) for any date and location via /zmanim
Convert dates between the Hebrew and Gregorian calendars via /converter
Compute upcoming yahrzeit and Hebrew anniversary dates from a Gregorian death/event date via /yahrzeit
Retrieve Torah leyning details (parsha, aliyot, haftarah) for a given Shabbat or holiday via /leyning
Use Cases
Patterns agents use Hebcal API for, with concrete tasks.
★ Synagogue Website Calendar
A synagogue website needs to display weekly Shabbat times and an annual holiday calendar without maintaining a Hebrew date library. The Hebcal API returns localized candle-lighting, havdalah, and holiday data keyed off city or coordinates so the site can render an accurate calendar with a single GET per page load. No API key is needed.
Call GET /shabbat?cfg=json&geonameid=5128581 and return this week's candle-lighting and havdalah times for New York
Hebrew Date Conversion Tool
An app that prints bar mitzvah certificates needs to convert a child's Gregorian birthday into the Hebrew date and back. The /converter endpoint handles bidirectional conversion in a single call, including the after-sunset edge case via the gs flag.
Convert the Gregorian date 1990-05-14 to its Hebrew equivalent by calling GET /converter?cfg=json&gy=1990&gm=5&gd=14&g2h=1
Zmanim and Yahrzeit Reminders
A reminder service computes daily halachic times and upcoming yahrzeit dates for users who provide their location and family records. The /zmanim and /yahrzeit endpoints return the full set of times and the next n yahrzeit occurrences in a single call, eliminating the need for in-house astronomical calculations.
Call GET /yahrzeit?cfg=json&years=10&type1=Yahrzeit&date1=1990-05-14 and return the next 10 yahrzeit dates
AI Agent Jewish Calendar Assistant
An AI agent answers questions like 'when is Pesach next year in London?' or 'what's this week's parsha?' by calling Hebcal through Jentic. Because Hebcal requires no auth, the agent's only job is to pick the right operation - Jentic surfaces it by intent search.
Search Jentic for 'get jewish holidays for a year', load the /hebcal operation, and return the holidays for 2026 in London
Key Endpoints
6 endpoints — jentic publishes the only available openapi specification for hebcal api, keeping it validated and agent-ready.
METHOD
PATH
DESCRIPTION
GET
/hebcal
Get Jewish calendar events for a year and location
GET
/shabbat
Get Shabbat candle-lighting and havdalah times
GET
/zmanim
Get halachic times for a date and location
GET
/converter
Convert between Hebrew and Gregorian dates
GET
/yahrzeit
Calculate yahrzeit and anniversary dates
GET
/leyning
Get Torah reading details for a Shabbat or holiday
GET
/hebcal
Get Jewish calendar events for a year and location
GET
/shabbat
Get Shabbat candle-lighting and havdalah times
GET
/zmanim
Get halachic times for a date and location
GET
/converter
Convert between Hebrew and Gregorian dates
GET
/yahrzeit
Calculate yahrzeit and anniversary dates
GET
/leyning
Get Torah reading details for a Shabbat or holiday
Why Jentic?
What agents get from Jentic-routed access to this vendor.
Setup
The Hebcal API needs no credential, so wiring it by hand is mostly formatting query parameters like geonameid, year, and date and reconciling responses with your other tools. Through Jentic you install once, import the Hebcal API from the API Directory, and your agent calls it with a consistent request and response shape.
Permission scoping
The Hebcal API is read-only and unauthenticated, with lookups spread across endpoints like /shabbat, /zmanim, and /converter, so limit the agent to the lookups it needs, such as getting Shabbat times or converting a Hebrew date. You choose the operations it may call, so anything outside that set is not included unless you add it.
Credential isolation
Hebcal is unauthenticated, so there is no credential to store or inject. Jentic still routes the call through your own Jentic One instance so it shares a consistent execution surface with your other tools.
Intent-based discovery
Agents search Jentic by intent such as 'get shabbat times' or 'convert a hebrew date', and Jentic returns the matching Hebcal operation with its input schema so the agent passes geonameid, year, or date directly without browsing the reference docs.
Related APIs
Alternatives and complements available in the Jentic catalogue.
FAQs
Specific to using Hebcal API through Jentic.
Why is there no official OpenAPI spec for Hebcal API?
Hebcal publishes documentation on hebcal.com but does not ship an OpenAPI specification. Jentic generates and maintains this spec so that AI agents and developers can call Hebcal via structured tooling. It is validated against the live API and kept up to date. Get started with Jentic One, the self-hosted execution layer.
What authentication does the Hebcal API use?
The Hebcal API requires no authentication - all six endpoints are public GETs. Through Jentic the agent calls them directly with no credential handling required.
Can I get Shabbat candle-lighting times for any city with this API?
Yes. GET /shabbat accepts a geonameid, zip code, or latitude/longitude pair and returns candle-lighting and havdalah times for the upcoming Shabbat at that location.
What are the rate limits for the Hebcal API?
Hebcal asks consumers to keep request volume reasonable; there is no published per-key quota since the API is unauthenticated. For sustained or high-volume use, cache responses by date+location since the underlying data only changes daily.
How do I get this week's Shabbat times through Jentic?
Run pip install jentic, have the agent search for 'get shabbat candle lighting times', load the /shabbat operation, and execute it with a geonameid or lat/lon for the user's city.
Does the Hebcal API include Torah reading information?
Yes. GET /leyning returns the parsha, aliyot breakdown, and haftarah for a given Shabbat or holiday, which is useful for synagogue calendars and study apps.
Can I limit what my agent is allowed to do with the Hebcal API?
Yes. Because you run Jentic One yourself, you decide which Hebcal operations your agent may call, so you can allow just the lookups it needs, such as GET /shabbat for candle-lighting times or GET /converter for Hebrew date conversion, while withholding /zmanim, /yahrzeit, or /leyning. Anything outside the set you import is not available to the agent unless you add it. Since the Hebcal API is read-only and unauthenticated, there are no credentials to scope, only the operations you expose.
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