The Moon's Clock Runs Faster — and It May Need Its Own Time Standard

Key Takeaways About the Moon’s Time Standard

• Moon time is moving by about 56 to 59 microseconds (millionths of a second) each day faster than it is on Earth. After 46.5 years, that comes out to about one second.
• The moon experiences more time dilation than Earth because of a difference in relative velocity.
• Though moon time and Earth time are only slightly off, researchers needed to establish a moon time zone for the safety of astronauts traveling to the moon.

In early 2026, NASA plans to launch its Artemis II mission, sending astronauts around the moon for what the agency describes as economic benefits, scientific discovery, and, ultimately, it will serve as a stepping-stone for crewed missions to Mars.

As the world prepares for the next phase of space exploration, scientists are grappling with how best to integrate systems for seamless communication and data transfer. One such hurdle is how time is kept on the moon and how it compares to time on Earth.

Read More: NASA’s Artemis II Mission Now Targeting March 2026 Launch After Fuel Test Issue

Lunar Time Is Slightly Faster Than Earth Time

Lunar time is slightly faster than on Earth — between just 56 and 59 microseconds (millionths of a second) each day. Over 46.5 years, that amounts to one second. Though such a brief blink of time might seem inconsequential to humans, proper timekeeping is essential for the synchronous operation of electronic equipment on the moon.

Avi Loeb, a professor of science and the founding director of Harvard's Black Hole Initiative, told Discover that if synchronous timing slips, we could not maintain a reliable record of events or the communication protocols of computers and other electronic equipment on the moon and Earth.

Why Is Time Faster on the Moon?

Time ticks faster on the moon because its gravitational potential well is shallower than Earth's, a concept known as gravitational time dilation. In other words, the Moon's weaker gravity causes the lunar clock to gain time, relative to clocks on Earth.

“It is larger than the average time dilation due to the second-order Doppler effect, which scales as the square of the velocity of the moon around Earth,” said Loeb to Discover. “Albert Einstein's General Theory of Relativity shows that time progresses more slowly in the presence of stronger gravity. The ultimate extreme is near the event horizon of a black hole, where time slows down to a halt from the point of view of a distant observer.”

Because of this, the moon needs its own time zone rather than using Earth-based time.

“If you were to observe a friend falling into a black hole, the ultimate image is frozen at the instant of crossing the event horizon. No information is available from inside the horizon,” Loeb told Discover. “The case of Earth is a modest version of the black hole's extreme, but time still slows down in its vicinity relative to the moon, which has weaker gravity.”

Calculating the Moon’s Timezone

The moon’s day-night cycle differs from Earth’s, and that matters for timekeeping. According to Loeb, the moon shows the same face to Earth, and as it orbits Earth over a month, it completes a day-night cycle relative to the sun.

In simple terms, for someone living or working on the moon, scientists would need to convert moon time to Earth hours to translate moon clock readings to Earth clock readings, said Loeb.

And for astronauts traveling between the moon and Earth, time would be altered as well. That’s because spacecraft time could tick even faster than on the surface of the moon.

It’s not just electronic equipment that is affected by gravitational potential. We, too, age differently because of these subtle differences.

“We are all embedded inside the gravitational potential well of the Milky Way galaxy with a fractional drift of about a part in a million, much larger than that of the Earth,” said Loeb to Discover. “Over a lifespan of 100 years, we age more slowly by 53 minutes than average cosmic residents of intergalactic space.”

Read More: Methane from Lunar Landers May Contaminate Ancient Organic Molecules at the Moon's Poles

Article Sources

Our writers at Discovermagazine.com use peer-reviewed studies and high-quality sources for our articles, and our editors review for scientific accuracy and editorial standards. Review the sources used below for this article:

• This article references information from NASA: What You Need to Know About NASA’s Artemis II Moon Mission