swissntp
DEFRITEN
Public Swiss NTP service

NTP servers Switzerland — precise, GPS-based and independent time.

Our own GPS/PPS Stratum 1 time base in Gähwil, directly available via stratum1-1/stratum1-2.ntp.swissntp.net, plus geographically distributed Stratum 2 servers over IPv4 and IPv6.

00:00:00.000
— · Europe/Zurich
UTC 00:00:00
The displayed clock is your device clock shown in Swiss time and UTC. It is not a measurement of SwissNTP server accuracy.
Public Stratum 1+2 Stratum 2 · NTP Pool IPv4 + IPv6 NTS · RFC 8915 NTP Pool · zone ch
01

Live status

The status API is currently unavailable. Live cards intentionally show no invented values. Previously loaded history data may remain visible.
Source: api.swissntp.net/status · Refresh every 60 s · Updated: —

Stratum 1 · GPS/PPS · public (Gähwil SG)

Public Stratum 2 servers

Offset history · Stratum 1 (GPS/PPS)

ms · rolling 24 h
Collecting measurements… the chart builds with every update.

Offset history · Stratum 2

ms · rolling 24 h
Collecting measurements… the chart builds with every update.
02

Configuration

Central hostname
ntp.swissntp.net
Resolves to all public Stratum 2 servers. Alternatively, configure ch1 through ch4.ntp.swissntp.net individually. To synchronise directly from GPS/PPS Stratum 1, manually configure stratum1-1/stratum1-2.ntp.swissntp.net; these servers are intentionally not part of the NTP Pool.
Classic NTP with chrony: maxsources 4 means that at most four active time sources from ntp.swissntp.net are used simultaneously. NTS: with SwissNTP, the servers must be configured using their individual hostnames (ch1–ch4 or stratum1-1/stratum1-2). ntp.swissntp.net must not be used for NTS because the TLS certificates are issued for the individual server names.
chrony.conf
03

Infrastructure

SwissNTP’s time base comes from two independent GPS-backed Stratum 1 time servers at Gähwil (SG). Both use GPS and PPS (Pulse Per Second) as their primary reference and operate independently. They are also directly available to the public at stratum1-1.ntp.swissntp.net and stratum1-2.ntp.swissntp.net for manual configuration outside the NTP Pool.

The Stratum 1 site in Gähwil is designed redundantly. The two time servers operate independently and provide a robust GPS/PPS time base.

All Stratum 2 servers synchronise exclusively with these own Stratum 1 sources; no third-party NTP sources are used. The Stratum 2 servers are geographically distributed across Switzerland to support high availability and low latency for Swiss clients.

2
GPS/PPS Stratum 1
4
Stratum 2 servers
6
Public servers
3
Locations in Switzerland
NTS
Authenticated · RFC 8915

Server overview

TypeHostnameLocationProviderNetworkNTS
Stratum 1stratum1-1.ntp.swissntp.netGähwil SGInit7IPv4 + IPv6Yes
Stratum 1stratum1-2.ntp.swissntp.netGähwil SGiWayIPv4 + IPv6Yes
Stratum 2ch1.ntp.swissntp.netZurichiWayIPv4 + IPv6Yes
Stratum 2ch2.ntp.swissntp.netGenevaInfomaniakIPv4 + IPv6Yes
Stratum 2ch3.ntp.swissntp.netGähwil SGInit7IPv4 + IPv6Yes
Stratum 2ch4.ntp.swissntp.netGähwil SGiWayIPv4 + IPv6Yes
SwissNTP participates in the public NTP Pool Project and makes its four Stratum 2 servers available through the Swiss pool zone. See the SwissNTP profile at ntppool.org. The two GPS/PPS Stratum 1 servers are directly public but intentionally not part of the pool.
04

Frequently asked questions

Which NTP servers does SwissNTP provide in Switzerland?

SwissNTP operates public time servers in Switzerland: two GPS/PPS-backed Stratum 1 servers in Gähwil (SG) and four geographically distributed Stratum 2 servers in Zurich, Geneva and Gähwil. All are reachable over IPv4 and IPv6.

Do the Swiss NTP servers support NTS?

Yes. The servers support Network Time Security (NTS, RFC 8915) over TCP port 4460 in addition to classic NTP over UDP port 123.

Why must SwissNTP servers be configured individually for NTS?

For NTS, use the individual hostnames such as ch1.ntp.swissntp.net through ch4.ntp.swissntp.net, or the two Stratum 1 hostnames. The TLS certificates are issued for these individual server names. The pool hostname ntp.swissntp.net is therefore not intended for NTS.

How do I configure SwissNTP?

For classic NTP with chrony use pool ntp.swissntp.net iburst maxsources 4. maxsources 4 limits the number of pool sources used simultaneously to at most four. For NTS, the individual server hostnames must be used instead. Examples are provided in the Configuration section.

Are the servers part of the NTP Pool?

The four Stratum 2 servers participate in the NTP Pool Project in zone ch. The two Stratum 1 servers are intentionally kept out of the pool.

Can I use SwissNTP with Synology, MikroTik or a Windows domain controller?

Yes. Any device supporting standard NTP can use ntp.swissntp.net or an individual SwissNTP server. In a Windows domain, the PDC Emulator is typically synchronised with external NTP sources.

What is the difference between SwissNTP and METAS?

METAS is the Swiss Federal Institute of Metrology and Switzerland’s official metrological reference. SwissNTP is an independent, free public NTP/NTS service with its own GPS/PPS Stratum 1 time base and is not an official time authority.

Can SwissNTP be used for building automation such as KNX or Loxone?

Yes, provided the device or gateway supports a configurable NTP server and UDP port 123 is reachable. Classic NTP continues to work on systems without NTS support.

Can I use SwissNTP behind a Swisscom Internet-Box?

Yes. Devices on the local network can use SwissNTP if they support a custom NTP server. Whether the router itself allows a custom NTP server depends on its model and firmware.