Does Windows Time Service (w32time) handle NTP 2036 rollover?

Hi Keiichi Kawaguchi (川口 圭一)

The Windows Time Service (w32time) in Windows 10 and 11 is built on NTPv3, which uses that 32‑bit seconds field you mentioned. By design, NTPv3 will hit the rollover in February 2036, so technically the risk is real. Right now, there isn’t official Microsoft documentation that explicitly confirms how w32time will handle the rollover, nor published test results that prove it’s already covered. The expectation is that future updates or a move toward NTPv4 (which uses 64‑bit timestamps) will be the way to mitigate this in long‑term deployments. For infrastructure planning, the safest bet is to keep systems patched, monitor Microsoft’s guidance as we get closer to that date, and consider external NTP sources that support NTPv4 if you’re designing systems expected to run beyond 2036.

In practice, most organizations will refresh OS versions or time services well before then, so the risk is more theoretical than immediate. Still, it’s smart to have this on your radar and document it as a dependency

If this explanation helps clear things up, please go ahead and hit “accept answer” so we know you’re good to go. If you need more information, feel free to leave a message. We are happy to help!