Shift EXIF times of pictures (fixes 'CreateDate', 'DateTimeOriginal', 'ModifyDate')

time_shift.py

#!/usr/bin/env python3
import datetime
import argparse
import math
import os
import sys
import time
import subprocess

def parse_args():
    def exists(path):
        if os.path.exists(path):
            return path
        else:
            raise argparse.ArgumentTypeError("File %s does not exist" % path)

    parser = argparse.ArgumentParser()
    parser.add_argument("--fake", "-f", action="store_true", default=False,
                        help="don't actually rename anything")
    parser.add_argument("offset", type=int,
                        help="offset hours", metavar="HOURS")
    parser.add_argument("files", type=exists, nargs="+", help="files to time shift")

    return parser.parse_args()

def change_all_exif_dates(path, hours_shift, fake=False):
    for tag in ('CreateDate', 'DateTimeOriginal', 'ModifyDate',):
        cmd = ['exiftool', '-%s%s=%d' % (tag, '+' if hours_shift >= 0 else '-', abs(hours_shift)), path]
        print("Running command:", " ".join(cmd))
        if not fake:
            subprocess.check_call(cmd)

def time_shift(files, offset, fake=False):
    for f in files:
        f = os.path.abspath(f)
        orig_mtime = datetime.datetime.fromtimestamp(os.path.getmtime(f))
        mtime = orig_mtime + datetime.timedelta(hours=offset)

        if mtime != orig_mtime:
            print("Adjusting timestamp on file from %s to %s" % (orig_mtime, mtime))
            new_seconds = time.mktime(mtime.timetuple())
            change_all_exif_dates(f, offset, fake)
            if not fake:
                os.utime(f, (new_seconds, new_seconds))

def main():
    args = parse_args()

    # Check that all the files exist
    time_shift(args.files, args.offset, args.fake)

if __name__ == "__main__":
    main()