idf-date-converter

A date tool for converting between the Gregorian calendar used in most everyday software and the Hebrew calendar used for Jewish dates and Israeli holidays. It also handles dual-date formatting, Israeli business days, and Shabbat times.

In plain words
What is it for?
Use it to convert dates, find Israeli holidays, format Hebrew and Gregorian dates together, count business days excluding Shabbat and holidays, and check candle-lighting or Havdalah times.
Why use it?
It prevents mistakes when a document or schedule must use Hebrew dates, holidays, or local working-day rules. It brings calendar conversions and related date calculations into one workflow.

Skill for Claude CodeCodex

Install

Getting it into your agent

One page per mod, every tool's command on it. A separate URL per tool would split the same page into five that compete with each other.

agentmods
npx agentmods add skills/squadcodercom/squadcoder/idf-date-converter
Any agent
npx skills add squadcodercom/squadcoder --skill idf-date-converter
Clone the repo
git clone --depth 1 https://github.com/squadcodercom/squadcoder

Made for: Claude Code, Codex.

Per session 137 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 2,410 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. Scan, not verified.
Origin original No closer match found in the catalogue.
Token cost

What it costs to keep this loaded

Counted locally with the o200k_base tokenizer, which is exact for GPT models; Claude uses its own tokenizer and its counts differ. Treat this as one consistent yardstick across the catalogue rather than a bill. Prices are per million input tokens.

ModelPer sessionOnce invoked
Fable 5 $0.00137 $0.02410
Opus 5 $0.00068 $0.01205
Sonnet 5 $0.00027 $0.00482
Haiku 4.5 $0.00014 $0.00241

Measured 2d ago against content hash 9cbd61289a70, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

idf-date-converter scanned grade A with 0 findings against 26 rules in 11 categories — prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency — measured 2d ago.

The scan reads SKILL.md. This mod also ships 1 executable file (scripts/convert_date.py), listed below but not scanned — reading those needs a real analyzer, not pattern matching.

A static scan of the body, not an audit. Every finding is printed with the line that produced it so you can judge whether it matters here. A mod is markdown that instructs an agent; that is exactly why what it instructs is worth reading.

Nothing flagged

None of the 26 patterns this scan looks for appear in this file: no shell pipes, no recursive deletes, no credential paths, no hidden text, no instruction-override or anti-refusal phrasing, no agent-config snooping. That is not a guarantee, it is the absence of the things that are checkable.

.squadcoder/skills/idf-date-converter/SKILL.md · 149 lines

How it starts

The opening of the file, as written. The whole thing — 149 lines — stays where its author put it; the contents beside it link to each section on GitHub.

IDF Date Converter

Instructions

Step 1: Identify the Request

Request Action
Convert specific date Gregorian to Hebrew or Hebrew to Gregorian conversion
When is holiday X? Look up holiday in Hebrew calendar
Format for document Dual date string in Hebrew + Gregorian
Business days Count excluding Shabbat + holidays
Shabbat times Candle lighting / havdalah for city

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 (always verify the resulting date by round-tripping)
heb_date = dates.HebrewDate(5786, 11, 15)  # 15 Shvat 5786 (Tu B'Shvat) — pyluach numbers months starting at Nisan=1, so Shvat=11
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 / 7 Adar 5786

(5786 is a regular Hebrew year, not a leap year, so there is only one Adar — no Adar I / Adar II. Always run pyluach to confirm a dual-date string before printing it.)

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)

Read the full file on GitHub · 149 lines

Files

What ships with it

5 files beside SKILL.md in the same directory: the scripts, references and assets a skill reads on demand. Not counted in the per-session cost; read them before you install if any of them is executable.

Changes

What this file has done since we first saw it

Hashed on every crawl. A supply-chain change to an agent config is a question of when, not whether, so the history is kept rather than the latest state alone.

  1. 2d ago First seen · 149 lines · 137 tokens per session scan A 9cbd61289a70

Subscribe to this mod's changes

idf-date-converter is a skill published in the GitHub repository squadcodercom/squadcoder (11 stars, last pushed 2mo ago), licensed MIT. It adds 137 tokens to every session and 2,410 once invoked, about $0.0007 per session on Opus 5. A static security scan graded it A with 0 findings. No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-30.

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