Add seconds to the Mac menu-bar clock

Out of the box, the Mac menu-bar clock shows hours and minutes only — 2:41 PM, and nothing more granular. That's a deliberate default, not a missing feature, and a single setting adds the seconds back. Here's where the option lives, plus the one-line command that does the same thing.

Why the clock stops at minutes

The menu bar is Apple's most tightly rationed real estate, and the clock's job there is to be readable at a glance and utterly still. A minutes-only clock repaints once a minute; a seconds clock repaints sixty times as often. On modern hardware that difference is negligible, but the minimal, motion-free default is a design choice that's held across macOS 13 Ventura, 14 Sonoma and 15 Sequoia. Seconds are treated as opt-in — genuinely useful for some people, unnecessary clutter for others — so Apple ships them off and leaves the switch one click away.

Add seconds in System Settings

1. Open System Settings and select Control Center from the sidebar.
2. Scroll down to the Clock section and click Clock Options.
3. Switch on Display the time with seconds.

The counter appears at once — no logout, no restart. That same Clock Options sheet holds the neighbouring choices for the clock: show the date, show the day of the week, show AM/PM, use a 24-hour clock and flash the time separators. If you've never opened it, it's the single place where the whole look of the menu-bar clock is decided.

Add them with one command

The preference is stored under a name you can set directly. Because the clock is rendered by the ControlCenter process, you restart that process to make the change appear:

# Add a seconds counter to the menu-bar clock
defaults write com.apple.menuextra.clock ShowSeconds -bool true
killall ControlCenter

Changed your mind and want the tidy minutes-only clock back? Write the opposite value and reload once more:

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

There's no risk in trying it: the command sets exactly one key, and the undo returns you precisely to the default state. If you ever want to wipe the key back to "unset" rather than explicitly false, defaults delete com.apple.menuextra.clock ShowSeconds followed by the same killall does that too.

Whichever route you take, the result is the same clock the default hides from you — the full 2:41:07 PM — sitting where the shorter version used to be.

Add the day and date too

Seconds is one of several things the default clock leaves off. To round out the readout with the weekday, see how to show the day of the week in the menu bar on Mac — set in the same Clock Options sheet.