IDF Date Converter

Step 1: Identify the Request

Step 2: Date Conversion

Use Python conversion:

# Using pyluach library
from pyluach import dates, hebrewcal

# Gregorian to Hebrew
greg_date = dates.GregorianDate(2026, 2, 24)
heb_date = greg_date.to_heb()
print(f"{heb_date.day} {heb_date.month_name()} {heb_date.year}")

# Hebrew to Gregorian
heb_date = dates.HebrewDate(5786, 6, 26)  # 26 Adar 5786
greg_date = heb_date.to_greg()
print(f"{greg_date.day}/{greg_date.month}/{greg_date.year}")

Step 3: Hebrew Numeral Formatting

Hebrew dates use gematria (letter-number system):

• Units: alef=1, bet=2, gimel=3, ... tet=9
• Tens: yod=10, kaf=20, lamed=30, ... tzadi=90
• Hundreds: kuf=100, resh=200, shin=300, tav=400
• Special: 15 = tet-vav (not yod-heh), 16 = tet-zayin (not yod-vav)
• Year: Omit thousands (5786 written as tav-shin-peh-vav = 786)

Step 4: Dual Date Formatting

For Israeli documents:

24 February 2026 / 26 Adar I 5786

Step 5: Israeli Business Days

Israeli business week: Sunday through Thursday (some work half-day Friday) Non-working days:

• Every Shabbat (Friday sunset to Saturday sunset)
• All major holidays (see holiday table)
• Election days (when applicable)

def is_israeli_business_day(greg_date):
    """Check if a date is an Israeli business day."""
    # Saturday = 5 in Python's weekday() (0=Monday)
    if greg_date.weekday() == 5:  # Saturday
        return False
    # Check if it's a holiday
    heb = dates.GregorianDate(greg_date.year, greg_date.month, greg_date.day).to_heb()
    # Check against holiday list
    return not is_israeli_holiday(heb)

Israeli Holidays (Fixed Hebrew Dates)

Example 1: Simple Conversion

User says: "What's today's Hebrew date?" Result: "24 February 2026 = 26 Adar I 5786"

Example 2: Holiday Lookup

User says: "When is Pesach 2026?" Result: "Pesach begins evening of April 1, 2026 (15 Nisan 5786). First seder: April 1. Last day: April 8."

Example 3: Business Days

User says: "How many business days between March 1 and March 31, 2026?" Result: Count excluding Shabbatot, noting if any holidays fall in the range (Purim on March 17).

Scripts

• scripts/convert_date.py — Converts between Hebrew and Gregorian calendars, formats dual dates for Israeli documents, lists Israeli holidays for any year, and counts Israeli business days between date ranges (excluding Shabbatot and holidays). Requires pyluach library. Run: python scripts/convert_date.py --help

References

• references/hebrew-calendar-reference.md — Complete Hebrew calendar reference covering month names and variable lengths, the 19-year Metonic leap year cycle, gematria (Hebrew numeral) conversion table with special cases, Israeli holiday calendar with work-off days versus partial-closure days, and recommended Python libraries (pyluach, hebcal). Consult when handling leap year edge cases, formatting Hebrew numerals, or determining which holidays affect business day calculations.

Error: "Incorrect Hebrew date"

Cause: Hebrew months vary in length; leap year months confusing Solution: Verify with hebcal.com. Adar I/II only exist in leap years. Current year (5786) leap status affects dates.