Show the seconds counter in the Mac menu bar

If your day has hard, to-the-second moments — a 9:30 market open, a ticket on-sale, a product drop, a livestream go-live — a clock that only shows minutes is a liability. Adding a seconds counter to the menu bar lets you count the last moments down without another app in front of you. Turn it on in Control Center, or with one Terminal command.

Add the counter in Control Center

1. Open System Settings → Control Center.
2. Scroll to the Clock section and click Clock Options.
3. Turn on Display the time with seconds.

The seconds appear immediately, next to the minutes in the top-right corner. On the run-up to a deadline you now watch :57, :58, :59 roll over rather than staring at a static minute and hoping. This works the same on macOS 13 Ventura, 14 Sonoma and 15 Sequoia.

The Terminal route

To set it from the command line — handy on a trading or events machine you configure the same way each time:

# Show the live seconds counter
defaults write com.apple.menuextra.clock ShowSeconds -bool true
killall ControlCenter

Reverse it just as easily when the event's over and you want the quieter clock back:

# Undo — hide the seconds counter
defaults write com.apple.menuextra.clock ShowSeconds -bool false
killall ControlCenter

Make sure you're watching the right clock

A seconds counter is only as trustworthy as the clock behind it. If your Mac's time has drifted, you'll be a few seconds early or late at exactly the moment that matters. Before anything time-critical, confirm your Mac is syncing to Apple's time servers:

1. Open System Settings → General → Date & Time.
2. Make sure Set time and date automatically is on.
3. Check that the Source reads an Apple time server (time.apple.com).

With automatic time on, macOS keeps your clock aligned to a network reference, so the seconds you see match the seconds the exchange or the on-sale server is counting. Two cautions worth holding in mind: the counter shows your clock, not the round-trip delay to a remote server, so on a busy on-sale your click still travels the network after the second you saw — build in that buffer. And if the corner ever shows a time you know is wrong, fix the clock first rather than trusting the counter.

Get the sync right and the seconds counter becomes what you actually want on a high-stakes day: a calm, always-visible readout of exactly where you are in the minute, with nothing to open and nothing to miss.

If the clock itself looks off

A wrong time defeats a seconds counter entirely. If the corner shows the wrong hour or the wrong day, see how to fix the wrong time on Mac before you rely on the count.