A hydrogen maser atomic clock aboard the satellite maintained synchronization with the ground station to within 0.45 nanoseconds over a 12-hour period.

The laboratory upgraded its hydrogen maser atomic clocks to improve long-term frequency stability for deep-space tracking.

In the dim ballroom, there were faces that would stop a clock, each more eerily beautiful than the last.

When discussing his rare good ideas, his friends joked that a broken clock is right twice a day.

Even though he contradicts himself constantly, remember that a stopped clock is right twice a day, so sometimes he's unexpectedly correct.

The clockless dining room made every meal feel unusually timeless.

At dusk, the old clocktowers cast long shadows across the cobblestone square.

Her clocklike routine reassured everyone in the hectic newsroom.

The antique clockcase was carefully restored by the museum's conservator.

The antique shop displayed several ornate clockcases that gleamed under the soft lights.