Agent skill
reverse-date
Convert dates from various formats (like "21 Oct 2025", "October 21, 2025", "21/10/2025") to ISO format (YYYY-MM-DD). Use when users need to standardize date formats, convert human-readable dates to machine-readable formats, or reformat dates for data processing.
Install this agent skill to your Project
npx add-skill https://github.com/majiayu000/claude-skill-registry/tree/main/skills/other/reverse-date
SKILL.md
Date Converter
Overview
Convert dates from various human-readable formats into standardized ISO format (YYYY-MM-DD). This skill handles flexible date input parsing and provides consistent, machine-readable output.
Usage
Use the convert_date.py script to convert any date string to YYYY-MM-DD format:
python scripts/convert_date.py "21 Oct 2025"
# Output: 2025-10-21
Supported Input Formats
The script accepts a wide variety of date formats, including:
- Month-day-year: "21 Oct 2025", "October 21, 2025", "Oct 21, 2025"
- Slash-separated: "21/10/2025", "10/21/2025"
- Dash-separated: "21-10-2025", "2025-10-21"
- Other common formats: Most standard date representations
Examples
# Human-readable format
python scripts/convert_date.py "21 Oct 2025"
# → 2025-10-21
# Full month name
python scripts/convert_date.py "October 21, 2025"
# → 2025-10-21
# Slash format
python scripts/convert_date.py "21/10/2025"
# → 2025-10-21
# Already in ISO format
python scripts/convert_date.py "2025-10-21"
# → 2025-10-21
Error Handling
If the date string cannot be parsed, the script returns an error message:
python scripts/convert_date.py "invalid date"
# Error: Unable to parse date: 'invalid date'. Error: Unknown string format: invalid date
Implementation Details
The script uses Python's dateutil.parser library for flexible date parsing, which handles many common date formats automatically. The output is always in ISO 8601 format (YYYY-MM-DD).
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