Update Markdown file creation dates

As I’ve migrated files between different apps over the years, in many cases the act of exporting or recreating notes has created inconsistency between the actual creation date (metadata in Finder) and the date metadata added to the top of the file in YAML front matter.

This is a simple utility that takes a directory, finds Markdown files, checks front matter for either date: YYYY-MM-DD or date: MM-DD-YYYY, and updates the file’s creation date using the macOS setfile command.

import os
import re
import subprocess
import sys
from datetime import datetime

def update_file_dates(directory):
    # Regex to match date in front matter
    date_pattern = re.compile(r'^date: (\d{4}-\d{2}-\d{2}|\d{2}-\d{2}-\d{4})')

    for root, dirs, files in os.walk(directory):
        for file in files:
            if file.endswith('.md'):  # or any other extension you're targeting
                file_path = os.path.join(root, file)
                    with open(file_path, 'r') as f:
                        for line in f:
                            date_match = date_pattern.match(line)
                            if date_match:
                                date_str = date_match.group(1)
                                # Handle different date formats
                                    if '-' in date_str:
                                        parts = date_str.split('-')
                                        if len(parts[0]) == 4:  # yyyy-mm-dd
                                            date_obj = datetime.strptime(date_str, '%Y-%m-%d')
                                        else:  # mm-dd-yyyy
                                            date_obj = datetime.strptime(date_str, '%m-%d-%Y')
                                        # Format date for setfile command
                                        formatted_date = date_obj.strftime('%m/%d/%Y %H:%M:%S')
                                        # Update file creation date
                                        subprocess.run(['setfile', '-d', formatted_date, file_path])
                                except ValueError as e:
                                    print(f"Error parsing date for file {file_path}: {e}")
                                break  # Stop reading file after finding the date
                except Exception as e:
                    print(f"Failed to process file {file_path}: {e}")

if __name__ == "__main__":
    if len(sys.argv) != 2:
        print("Usage: python update_file_dates.py <directory>")
    directory = sys.argv[1]


python3 update_file_dates.py /path/to/your/documents

This script can be easily adjusted to support .txt files, other date front matter like created, or other date formats, if needed. Reach out if you have any questions or recommendations for improvements.