Frontmatter Date Manager

Automatically update created, updated, and viewed dates in YAML frontmatter when editing notes in Obsidian.

Why this plugin?

• Manual timestamp maintenance is tedious. Updating created and updated in frontmatter by hand every time you edit a note is error-prone and breaks your writing flow.
• Obsidian has no built-in frontmatter date management. It tracks ctime/mtime at the filesystem level but doesn't automatically write or maintain date properties inside your notes.
• Sync tools cause false updates. Obsidian Sync, iCloud, Syncthing, Dropbox, and Git-based sync modify files without real content changes. Without content hashing, every sync would trigger a timestamp update - creating noise and potentially infinite sync loops.
• Templates and automation plugins conflict. Templater, Daily Notes, QuickAdd, and similar plugins create and immediately modify files. Without a configurable delay, timestamps get written before the template is fully applied, resulting in incorrect dates.
• Existing vaults lack timestamps. When you adopt the plugin on a vault with hundreds or thousands of notes, you need a way to bulk-populate timestamps from filesystem dates - not update each note one by one.
• Manual entry leads to inconsistent formats. Different notes end up with 2024-01-15, Jan 15, 2024, 15.01.2024, and other variations. The plugin enforces a single configurable format across the entire vault.
• No automatic "last opened" tracking. Obsidian tracks when a file was modified but has no concept of when you last read it - and no other plugin writes this into frontmatter. This plugin can optionally stamp a viewed date every time you open a note, making it queryable via Dataview for spaced repetition, review workflows, and "what haven't I looked at in months?" dashboards.

Features

• Auto-update updated field on file modification (syncs with mtime)
• Auto-set created field on new files (syncs with ctime)
• Auto-set viewed field when a file is opened - unique feature not found in other plugins (disabled by default)
• Customizable date format (uses date-fns syntax)
• Timezone support with IANA timezone autocomplete
• String and number property types (number useful for Unix timestamps)
• Gitignore-style file filter rules with preview and validation
• Configurable minimum interval between updates
• Delay for newly created files (compatibility with Templater, Daily Notes, etc.)
• SHA-256 content hashing to detect real changes (prevents false updates from sync tools)
• Hash tracking mode: body only, frontmatter only, or both
• Frontmatter key exclusion from change detection
• Run a command after timestamps are updated
• Bulk-update all vault files at once
• Bulk-populate timestamps from filesystem dates (ctime/mtime) with dry-run preview
• Rename frontmatter keys across all files (migrate old key names with preview)
• Reformat existing dates from one format to another (parse old, write new, with preview)
• Toggle auto-update via command palette or status bar
• Pause auto-update for 5 minutes with automatic resume
• Works on desktop and mobile

Installation

Manual installation

Download main.js, manifest.json, and styles.css from the latest release into <vault>/.obsidian/plugins/frontmatter-date-manager/.

Community plugins (coming soon)

This plugin has been submitted to the Obsidian community plugin directory. Once approved, search for Frontmatter Date Manager in Settings > Community plugins > Browse.

Usage

The plugin runs automatically after installation. When you edit a markdown file, it updates the frontmatter updated field with the current modification time. If the created field is missing, it sets it to the file's creation time. Optionally, enable the viewed timestamp in settings to record when you last opened each file.

Configure behavior in Settings -> Frontmatter Date Manager.

Commands

Status bar indicator - shows current state (Paused or Paused (Xm)); click to toggle auto-update on/off.

Settings

Date format examples

Note: This plugin uses date-fns, not Moment.js. Common migration: YYYY -> yyyy, DD -> dd.

FAQ

First installation

Will the plugin modify all my existing notes when I first enable it?

No. The plugin only processes a file when you edit it. On first load it builds a background hash cache of your existing files to prepare for change detection, but it never writes timestamps during this process. Your vault stays untouched until you actually edit a note.

How do I add timestamps to notes I wrote before installing?

Use Settings → Bulk operations → Populate from filesystem. It reads filesystem dates (ctime/mtime) and writes them into frontmatter, with a dry-run preview so you can review before committing. Default mode is "Fill missing only" - existing dates are not overwritten. If your vault syncs via iCloud or Obsidian Sync, filesystem timestamps may have been reset by the sync service - review the preview carefully.

I use Templater / Daily Notes / QuickAdd. Will the plugin conflict with them?

No. The plugin waits 5 seconds (configurable: Settings → Behavior → Advanced → New file delay) before processing newly created files, giving template plugins time to finish.

Do I need to add frontmatter to every note manually first?

No. If a note has no frontmatter, the plugin creates the --- block and inserts timestamps on the next edit. If frontmatter already exists, it adds timestamp fields alongside your existing keys.

What date format works best with Dataview?

The default yyyy-MM-dd'T'HH:mm:ss (ISO 8601) works out of the box. Dataview can parse, sort, and compare it natively.

The plugin uses date-fns, not Moment.js. Does that affect me?

Only if you customize the date format. Key difference: use yyyy (not YYYY) for year, dd (not DD) for day. The plugin shows a hint in settings if it detects a Moment.js-style format.

Everyday usage

I enabled "viewed" timestamps but they don't appear in some notes.

The viewed timestamp is only written when you open a file. Notes you haven't opened since enabling the feature won't have the field yet. The same filter rules and minimum-interval setting apply to viewed writes.

I edited tags or aliases, but updated didn't change. Is that a bug?

No. By default, hash tracking mode is "Body only" - only changes below the frontmatter block trigger a timestamp update. To include frontmatter changes, switch Settings → Change detection → Tracking mode to "Both".

Will syncing (iCloud / Obsidian Sync / Dropbox) cause false timestamps?

No. The plugin compares file content via SHA-256 hashing. If a sync service rewrites a file without changing its content, the hash matches and no timestamp is updated. Enabled by default.

I renamed or moved a note. Does the plugin lose track of it?

No. The hash cache entry is automatically migrated to the new path. Existing timestamps are preserved.

I changed the date format. Will old timestamps be converted?

Not automatically. Use Settings → Bulk operations → Reformat dates to standardize all values. The plugin auto-detects existing formats (ISO 8601, European, US, numeric timestamps) and rewrites them using your current format. Preview all changes before applying.

I renamed the frontmatter key (e.g. created → date_created). What about existing files?

Use Settings → Bulk operations → Rename key. Enter the old and new key names, preview affected files, then apply. You can choose whether to delete the old key or keep both.

I changed the timezone. Will old timestamps be recalculated?

No. Same principle - old values are left untouched. New writes use the new timezone.

What happens if a note has broken YAML frontmatter?

The plugin skips that file and shows a notice with the file path and error details. It never writes to a file with malformed YAML. Fix the syntax and the plugin will pick it up on the next edit.

I'm saving rapidly. Will the timestamp update on every save?

No. There is a minimum 30-second interval between updates (configurable: 5–300 seconds) plus a 2-second debounce, so rapid edits are consolidated into a single timestamp write.

Sync and version control

The plugin stores a local cache file hash-cache.json inside its data directory (.obsidian/plugins/frontmatter-date-manager/). This file contains SHA-256 hashes used for content change detection. It rebuilds automatically on startup, so excluding it is safe and recommended.

Why exclude: the cache updates on every file edit, so multiple devices modify it independently - causing frequent sync conflicts and unnecessary traffic. Since it rebuilds automatically, syncing provides no benefit.

Add to your .gitignore:

.obsidian/plugins/frontmatter-date-manager/hash-cache.json

For Obsidian Sync: the file is already excluded automatically (Sync does not sync plugin data files beyond data.json).

For iCloud, Syncthing, Dropbox, or other file-based sync: add hash-cache.json to your sync tool's ignore/exclusion list for the plugin directory.

Development

make              # Show all available commands
make install      # Install dependencies
make pre-commit   # Run all checks (format, lint, test, build)
make local-test   # Build and copy plugin to local vault

To use make local-test, create a .env file with OBSIDIAN_VAULT=/path/to/vault, or pass it directly: make local-test OBSIDIAN_VAULT=/path/to/vault.

License

MIT