Meta Data Modifier

Support and help

Change created, modified and last-opened dates across many files at once — and edit the author details stored inside PDFs, photos and Office documents.

Requirements

macOS 13 Ventura or later. Apple silicon and Intel.

Getting started

1. Drag files and folders onto the window, or click + to pick them.
2. Choose a mode on the right — Set Date/Time, Adjust By or Sequence — and set the values you want.
3. Check the blue preview in the list, then press Apply. Press ⌘Z if you change your mind.

The app never changes anything until you press Apply, and the list always shows both the current date and the one that will replace it.

Frequently asked questions

Why does it ask for permission to a folder?

Meta Data Modifier runs in Apple's App Sandbox and can only reach files you hand it directly. Dropping a folder on the window grants access to that folder and its contents, and nothing else. It has no access to the rest of your Mac.

Why can't I change "Date Added" or the attribute-change date?

Neither can be written by any app. The attribute-change date (ctime) is maintained by macOS itself and updates whenever any metadata changes. "Date Added" is stored in the volume's own directory index, and macOS provides no way to set it. Both are shown in the app, clearly marked read-only, rather than being silently ignored. Choose Help ▸ What Can Be Changed for the full list.

Can I change the author of an old .doc, .xls or .ppt file?

You can read it, but not change it. Those are OLE2 compound files, and rewriting one in place risks corrupting the document. Converting the file instead would lose its formatting. Modern .docx, .xlsx and .pptx files are fully editable, including the "Last Modified By" field.

Why can't I set the dates stored inside a PDF?

The macOS PDF framework regenerates a document's internal creation and modification dates every time it saves, discarding anything an app sets. The PDF's author, title, subject and creator can all be changed, and the file's own dates in Finder are unaffected by this limitation.

Where is the author stored for a .txt, .md or .xml file?

Plain text files have nowhere inside them to keep an author, so the values go into macOS extended attributes — the same mechanism the system uses to attach Finder comments and "where from" information. Your file's text is never rewritten.

One caveat worth knowing: extended attributes travel with the file on Mac disks, but are dropped by FAT and exFAT drives, most ZIP archives, and email attachments.

Does editing metadata change my document's contents?

No. Text files use extended attributes and are not touched at all. For PDFs, images and Office documents only the metadata section is rewritten — image pixel data is copied through without re-encoding, so editing a JPEG's author does not reduce its quality.

Applying twice shifted my dates twice — how do I avoid that?

It shouldn't. "Adjust By" measures from each file's date as it was when you added it, so applying the same shift twice gives the same result rather than doubling. If you do want to shift again from the new dates, press Refresh in the toolbar first.

Something failed. Where do I look?

Open the log window from the toolbar or Window ▸ Processing Log. It records every file that failed and why, and exports as JSON.

Can I undo?

Yes. ⌘Z restores the previous dates exactly. When you edit document metadata the original file is copied aside first, so undo puts the original bytes back. Backups live in a temporary folder and are removed when you quit.