Complete Israel Calendar: Hebrew Dates, Holidays & Observances

Israel Calendar Conversion Guide: Hebrew Months, Dates & Holiday Mapping

Overview of the Hebrew (lunisolar) calendar and how it differs from the Gregorian calendar.
Month-by-month Hebrew calendar summary: names, approximate Gregorian date ranges, typical month lengths, and which months are leap-month candidates.
Rules for converting dates between Hebrew and Gregorian systems (basic method and common tools).
How Jewish holidays map to Hebrew dates and how those dates shift in the Gregorian calendar each year.
Special cases: leap years with an extra month (Adar I/Adar II), variable month lengths (Cheshvan/Kislev), and rules for holiday postponements (deḥiyyot).
Practical conversion aids: sample lookup table, algorithm references (e.g., Gauss/Mathematical methods), and recommended online converters or libraries.
Use cases: planning events, scheduling observances, software/calendar integration, and printing annual calendars.

The Hebrew calendar is lunisolar: months follow lunar cycles; years are adjusted with a 19-year Metonic cycle that inserts 7 leap months.
Months (common sequence): Nisan, Iyar, Sivan, Tammuz, Av, Elul, Tishri, Cheshvan (Heshvan), Kislev, Tevet, Shevat, Adar (Adar II in leap years).
Major holiday mappings:
- Rosh Hashanah — 1–2 Tishri (falls in Sept–Oct)
- Yom Kippur — 10 Tishri
- Sukkot — 15–22 Tishri
- Hanukkah — 25 Kislev (Dec)
- Purim — 14 Adar (or 14 Adar II in leap years)
- Passover (Pesach) — 15–22 Nisan (Mar–Apr)
Leap years add Adar I before Adar II; Purim is observed in Adar II.
Some months vary: Cheshvan and Kislev can be 29 or 30 days, causing annual calendar length differences.

For one-off conversions, use a reputable online converter or built-in calendar tools (examples: Hebrew calendar converters, library functions in Python/JavaScript).
For algorithmic conversion: implement rules based on molad calculations, postponement rules (deḥiyyot), and the 19-year Metonic cycle — or use established libraries (recommended to avoid implementing from scratch unless needed).
When planning across years, account for leap-year placement and variable month lengths.

Year-by-year example tables showing Hebrew ↔ Gregorian mappings for a sample range (e.g., 2024–2028).
A printable quick-reference card: month names, lengths, and holiday dates.
Links or references to reliable converters and calendar libraries (e.g., Hebcal, ICU, or language-specific packages).
Short code examples for common languages (Python, JavaScript) using libraries.