Core networking

time.apple.com

time.apple.com and time-macos.apple.com are Apple's time servers. Apple lists them as “Used by devices to set their date and time”, over NTP on UDP port 123.

Run by ApplePorts: 123 UDPChecked: 1 November 2026

Short answer

Apple's time servers. Macs use NTP on UDP port 123 to set their date and time from them.

Don’t block

Don't block them unless the Mac uses another time server. A clock that drifts makes secure websites fail with certificate errors.

Matches
time.apple.com time-macos.apple.com

A name with *. covers every name under it: *.push.apple.com matches 1-courier.push.apple.com.

What it serves

Apple's enterprise host list names time.apple.com for all its platforms and time-macos.apple.com for macOS only, both on UDP port 123.

On a Mac, timed keeps the clock right with NTP. It reads its server from /etc/ntp.conf, which the Date & Time settings change.

Each request and answer is a few small packets.

Processes that use it

timedPart of macOS. It keeps the clock correct with NTP, so it sends small requests to a time server such as time.apple.com.Process →

What breaks if you block it

Don’t block

Don't block them unless the Mac uses another time server. A clock that drifts makes secure websites fail with certificate errors.

What breaks if you block it

  • The Mac's clock drifts. Secure sites can then show certificate errors, such as ERR_CERT_DATE_INVALID.
  • Sign-ins and other features that check the time may fail.

With Kilobat Pro and the network filter, you can block a host for every app or for one app: in Connections, select a connection and choose Block. Apple’s own services are never blocked by Kilobat’s Protection lists.

Notes

On a network that blocks these servers, set a time server that the network allows in System Settings › General › Date & Time.

Apple’s rules for its hosts

Apple’s list, Use Apple products on enterprise networks, says that devices open these connections, not Apple’s servers. Apple services fail any connection that uses HTTPS interception, so a proxy that inspects TLS should leave Apple’s hosts alone.

If a firewall allows hosts by name, allowing *.apple.com covers most Apple services, Apple says. A firewall that works only with addresses can allow 17.0.0.0/8 for IPv4, and 2403:300::/32, 2620:149::/32 and 2a01:b740::/32 for IPv6.

To see which app on your Mac opened a connection to this host, use Kilobat’s Connections tab, or the agent network log for AI agents.

Sources

Checked on 1 November 2026.