Nerzen NTPVerified time from Istanbul, open to everyone
We don't trust our clock to a single source: we listen to twelve stratum 1 servers in six countries — national time laboratories and satellite-disciplined clocks — at the same time, and discard any that disagree with the rest. The result is a free time service with authentication (NTS) and no registration, a few milliseconds away from anywhere in Türkiye.
- IPv4
- 141.98.50.237
- IPv6
- 2a0f:bf01:0:1::3
- NTP
- 123/udp
- NTS-KE
- 4460/tcp
Comparing your device's clock with the server's clock.
Live status
updated every 15 seconds · —
System clock offset
Query rate
Traffic
since the service was last started
How a second reaches you
five steps from source to client
Atomic clocks
The world's official time (UTC) is an average of caesium and hydrogen maser clocks in national laboratories. Navigation satellites also carry atomic clocks traceable to the same scale.
Stratum 1 servers
Servers connected directly to these clocks make the time available on the network. We use two kinds together: national time laboratories and satellite (GNSS) disciplined servers.
Cross-checking
chrony continuously measures each source's offset and error bound. A source that disagrees with the majority is discarded; the clock is not updated unless at least three sources agree.
The Nerzen clock
The clock on our server in Istanbul is never stepped; its frequency is adjusted with parts-per-million precision so that it locks smoothly onto the selected source.
The answer to you
The same clock answers plain over NTP and authenticated over NTS. Its state is shown live on this page and in status.json.
Our time sources
live · all stratum 1 · the "Now" column shows which source is in use
| Country | Type | Stratum | Protection | Now | Offset | Error bound | Last response |
|---|---|---|---|---|---|---|---|
| Loading sources… | |||||||
Our clock is compared against all of these servers continuously. Because they are spread across independent organisations and different countries, even if one of them is completely wrong or unreachable the others outvote it and the service carries on without interruption. Only sources authenticated with NTS steer the clock; plain NTP sources are kept under observation for comparison, so a response altered in transit cannot shift our clock. The Offset column is the measured difference between the source and our clock; for distant sources most of that difference comes not from the clock but from the outbound and return paths being unequal — see the measurements page for details.
Why this instead of a random pool server
figures come from this server's live measurements
| Default / random pool server | time.nerzen.com | |
|---|---|---|
| Who operates it | Volunteer servers of unknown identity that can change with every query | A single, known operator; status and sources are published on this page |
| Distance to the source | Mostly stratum 2–3, upstream unknown | Stratum 2: connected directly to twelve stratum 1 servers |
| Resilience to a bad source | The server's own source count and selection are not visible | The clock is not updated unless at least three sources agree; dissenters are discarded |
| Authentication | None — the response can be altered in transit | NTS (RFC 8915): cryptographic proof that the response really came from us |
| Network path from Türkiye | May leave the country; 30–80 ms round trip, risk of asymmetry | In Istanbul; a few milliseconds from domestic networks |
| Servers and VPSs on the same network | Over the internet, on the order of milliseconds | In the same data centre; stability on the order of microseconds |
| Transparency | No measurements published | Offset, delay, source status and traffic are published every 15 seconds |
An honest note: this is not a stratum 1 server; we have no atomic clock or satellite receiver of our own. Our accuracy is limited by the quality of the network path to the selected stratum 1 source, and the error bound we publish (half the root delay + root dispersion) shows that as it is. For a distant client, accuracy is mostly determined by its own network path.
Who we serve
only totals are kept · individual IPs are not recorded
Signed time and time proof
beyond NTP: verifiable time
Roughtime
From the same clock, time where every reply is signed with Ed25519. A safe start for devices that do not know the time, proof against a server that lies, document stamping. time.nerzen.com:2002
Open Roughtime →Time Proof
Every minute of our clock in a signed transparency log: state, error bound, source changes. Verify a past moment in your browser and download the proof bundle.
Query a moment →Quick setup
use the hostname, not the IP — you won't be affected if the address changes
server time.nerzen.com iburst nts ntsdumpdir /var/lib/chrony
server time.nerzen.com iburst
# /etc/systemd/timesyncd.conf
[Time]
NTP=time.nerzen.comw32tm /config /syncfromflags:manual ^ /manualpeerlist:"time.nerzen.com,0x8" w32tm /config /update w32tm /resync
sudo systemsetup -setnetworktimeserver time.nerzen.com sudo systemsetup -setusingnetworktime on
/system ntp client set enabled=yes /system ntp client servers add address=time.nerzen.com
For Cisco, Juniper, pfSense, ESXi, Proxmox, Synology and others, see the setup page.
What breaks when the clock drifts
the ones at the top show up within minutes, the ones at the bottom stay silent for months
Kerberos / Active Directory
Logons stop entirely; by default, ticket freshness is limited to this window.
TOTP / two-factor authentication
Codes are rejected. Any difference between the server and the phone shifts the window.
TLS certificates
A valid certificate is rejected; a clock that runs ahead or behind has the same effect.
Session and token lifetimes
JWT, signed-cookie and cache lifetimes go wrong; sessions drop early or close late.
Logs and event correlation
When logs from systems with different clocks are merged, events appear in the wrong order.
Databases and replication
Timestamp-based ordering breaks down and silently produces inconsistent data.
Read on
Setup
chrony, timesyncd, ntpd, Windows, macOS, MikroTik, Cisco, Juniper, pfSense, ESXi, Proxmox, NAS, OpenWrt and containers.
Open →Verification
Measuring without touching the system clock, what values to expect, and fixes for common problems.
Open →Frequently asked questions
NTP and NTS, stratum, leap seconds, IPv6, usage rules.
Open →About
Infrastructure, accuracy budget, source policy, configuration and honest limits.
Open →Other open services from Nerzen
from the same network, free in the same way