Slack Teammate Time

How it works

Three steps, then it disappears

Install once. After that it just shows the times, quietly, and stays out of your way.

Install & it self-connects

On first launch it attaches to the Slack desktop app already on your Mac — locally, over a localhost-only debug port. No password, no OAuth, no workspace admin.

It reads timezones from Slack

Using the token already in the page, it asks Slack's own API for each teammate's timezone and caches it. Nothing leaves your Mac.

Inline & live

Each sender's local time appears next to their name and refreshes every minute. A menu-bar toggle turns it on/off instantly — no reload.

Features

Small app, genuinely useful

Inline

Local time by every name

Each teammate's current local time, refreshed every minute — no profile hover required.

Context

Sent-time + now

Older messages also show the sender's local time when they sent it, so timestamps make sense across zones.

Live

One-click on/off

A menu-bar clock toggles the feature on or off. Slack reloads so the helper reconnects cleanly.

Yours

Pick what to show

Current local time, sent local time, and how long ago — flip any part from the menu. Option changes apply live.

Age

How long ago

See 29m ago, 2h ago, or Yesterday next to the name — the missing “recent” cue Slack’s clock doesn’t spell out.

Clean

Bots & apps skipped

Automated senders never get a label, so the message list stays tidy.

No strings

No admin, no login

It reuses the Slack session already on your Mac. Works on personal and company workspaces alike.

Light

Featherweight

The helper idles at ~15 MB RAM and is event-light. The menu-bar app is a tiny native binary.

Set & forget

Always on

Starts at login, runs continuously, restarts itself if needed. No daily relaunch, no Mac restart.

Native

Universal & tidy

One app for Apple Silicon and Intel. Menu-bar only — and Slack's look and feel is untouched.

Plug & play

No code barrier

Download a .dmg, double-click the app, done. No Terminal, no Node.js to install — it's bundled.

Security & privacy

Local by design, safe by default

Reviewed automatically with no critical, high, or medium findings — plus defensive hardening.

Everything stays on your Mac

The injected script only talks to Slack's own same-origin API — the same thing the official client does. No analytics, no telemetry, no third-party servers.

Your token never leaves Slack's origin

It's read from the page and only sent to same-origin users.info — never logged, never written to disk, never sent anywhere else.

Localhost-only & no XSS

The debug port binds to 127.0.0.1 with a single allowed origin (not *). All injected text uses textContent, never innerHTML.

No elevated privileges

Everything runs as your user — no sudo, no setuid. Slack itself is never modified, and the deployed runtime is locked to your account.

Honest note: enabling the debug port lets any program already running on your Mac as you connect to Slack locally — inherent to this approach. It's restricted to localhost + one origin to block remote/web attackers. Use on demand and Uninstall if that's not right for you. This is an unofficial, local enhancement that only reads timezone info Slack already shows on profiles.

For remote teams

Made for how distributed teams actually work

Ping at the right hour

See at a glance whether it's 9 AM or 9 PM for someone before you message — fewer 2 AM buzzes.

Zero discipline required

No profile hovering, no mental math. The time is just there, every message.

Nothing for your team to adopt

It's local to your Mac. No app to roll out, no admin to convince, no one else affected.

Slack stays Slack

The label blends into the existing UI. No theme changes, no clutter, no broken aesthetic.

Install

Plug & play — about a minute

Download SlackTeammateTime.dmg and open it.
Double-click the SlackTeammateTime app.
First launch only: right-click → Open → Open (it's free & unsigned, so Gatekeeper asks once).
Click OK. A clock appears in your menu bar — done.

No Apple Developer signature ($99/yr) means macOS shows a one-time "unidentified developer" prompt. Right-click → Open clears it for good. After that it opens normally and starts at every login.

Download View source on GitHub

macOS	11.0 Big Sur or later
Chip	Apple Silicon or Intel (universal binary)
Slack	Native desktop app, signed in
Download	One .dmg · no prerequisites (Node bundled)
Price	Free & open source (MIT)
Mobile?	Slack already shows local time on a profile on mobile; this removes the extra tap on desktop. Why not mobile →

About the maker

Gobinda Tarafdar

WordPress product marketer · stubborn problem-solver · lifelong Harry Potter devotee

By day I'm the Product Marketing Specialist at WPBakery — the page builder that quietly powers a sizeable corner of the WordPress universe. Before that, I helped a single plugin cross 400,000+ active users. When the day-job owl flies home, I tinker on my own little workshop of spells — Slack Teammate Time is one of them.

WPBakeryThe page builder I market. DocscriberDocumentation, conjured. TheRecallerA memory charm for the web. TheEditraA video-editing cauldron. The Quill PressTech news, Daily Prophet style. CostlasCost-of-living, 140 countries.

Why I built this

Slack already knows everyone's local time — but it's hidden behind a hover, and it slips your mind exactly when you need it.

I kept doing the mental math wrong, or pinging a teammate right in the middle of their evening. I wanted that time right there in the conversation — but I didn't want to bother a workspace admin or push everyone onto a Marketplace app most of them would never need.

So I built a tiny thing for myself that just shows it — inline, quietly, without breaking Slack's look and feel. It runs entirely on your own Mac, needs no admin and no login, and it's free. It's especially handy for remote teams across timezones. If you've ever felt the same, it's yours too.

Know your teammate's
local time, right in Slack.