Free, stable, and highly available Public NTP Time Synchronization Service

A free time-synchronization service available to Internet users across Asia. It provides an extremely accurate UTC network time reference for your servers, network devices, and IoT devices.

NTP Domain Name (Recommended)

ntp.bdtime.cn

IPv4 Address (Reserved)

61.149.15.93

Agreement: NTP/SNTP | Port: UDP 123
Basic Information

What is NTP?

NTP is Network Time Protocol An acronym for "Internet Time Protocol," which is commonly referred to in Chinese as "Network Time Protocol." It is used to synchronize the system time of computers over a network and is widely used in servers, computers, switches, routers, cameras, databases, logging systems, financial systems, industrial control systems, and various networked devices.

For the core NTPv4 standards, see RFC 5905. The goal of NTP is to ensure that clients and servers synchronize around a unified UTC Time Reference Maintain consistency; time zone and daylight saving time settings are handled separately by the operating system or application, and NTP itself is not responsible for setting the local time zone.

Simply put, NTP ensures that networked devices know the “exact current time,” thereby guaranteeing that operations such as logging, authentication, scheduling, database replication, and industrial timing all run on the same timeline.

Why is accurate time so important?

NTP (Network Time Protocol) allows networked devices to know the “exact current time.” Many business systems may appear not to rely on time, but in reality, they all require a consistent, trustworthy, and traceable time reference.

Server Operations and Security

Ensure that log timestamps are consistent across multiple nodes to facilitate troubleshooting, alert correlation, attack attribution, and SIEM security audits.

Distributed Systems and Databases

Transaction processing, data backup and recovery, master-slave replication, task scheduling, and message queues all require an extremely strict, unified timeline.

Authentication and HTTPS

HTTPS/TLS certificate validity checks, Kerberos authentication, dynamic tokens, and API signing all rely heavily on the system time window.

Internet of Things (IoT) devices

Sensor data collection, event reporting, and remote control commands all require precise timestamps to ensure the validity of time-series data.

Video Surveillance and Security

The recording time of surveillance footage, the time an alarm is triggered, and subsequent legal evidence collection must all ensure absolute temporal accuracy.

Industrial and Energy Systems

Sequence of Events (SOE), state transitions, and data acquisition synchronization in industrial control systems all require a unified time reference.

Hardware-Level Time Source Assurance

Time synchronization via fusion of an internal rubidium atomic clock and GNSS satellites

The upstream infrastructure of the BDTIME public NTP service is built upon multiple GNSS time sources, such as BeiDou and GPS, and consists of a highly available cluster comprising three independent time-synchronization devices.

Each device comes with a built-inRubidium atomic clock. Even under extreme conditions (such as loss of satellite signal), it can still provide extremely stable time-keeping capabilities. Within 24 hours of losing the lock, the deviation from the satellite time source can be kept within Within 500 nanosecondsThe

We have joined NTP Pool Project, providing public-interest routing support to users in the Asia region.
Cluster Status
All Nodes Active
Node A (Rubidium)
Locked
Node B (Rubidium)
Locked
Node C (Rubidium)
Locked

Equipment Configuration Guide

Please select your operating system or device type to view the specific configuration steps. We recommend expanding the configuration panel to view the detailed code.

Method 1: Use chrony (Recommended)

Most modern Linux distributions (such as CentOS 8+ and Ubuntu 20.04+) recommend using chrony.

# 1. Install chrony (select the version appropriate for your distribution)
sudo apt install chrony    # Debian/Ubuntu
sudo yum install chrony    # CentOS/RHEL

# 2. Edit the configuration file
sudo vi /etc/chrony/chrony.conf  # Debian-based Path
# or sudo vi /etc/chrony.conf    # Red Hat-based path

# 3. Add the following to the configuration file
server ntp.bdtime.cn iburst

# 4. Restart the service and configure it to start automatically at boot
sudo systemctl restart chronyd
sudo systemctl enable chronyd

# 5. Check the synchronization status (* indicates successful synchronization)
chronyc sources -v
chronyc tracking

Method 2: Use systemd-timesyncd

# 1. Edit the configuration file
sudo vi /etc/systemd/timesyncd.conf

# 2. Modify or add the following content
[Time]
NTP=ntp.bdtime.cn
FallbackNTP=pool.ntp.org

# 3. Restart the service and enable it
sudo systemctl restart systemd-timesyncd
sudo timedatectl set-ntp true

# 4. View Status
timedatectl status
timedatectl timesync-status

Method 3: Using the Traditional NTPD

# Edit /etc/ntp.conf and add the following:
server ntp.bdtime.cn iburst

# Restart Service
sudo systemctl restart ntpd
sudo systemctl enable ntpd

# Check Status (* indicates successful synchronization)
ntpq -p

Command-line method (Requires administrator privileges to run cmd or PowerShell)

# Configuring a Time Source
w32tm /config /manualpeerlist:"ntp.bdtime.cn,0x8" /syncfromflags:manual /update

# Restart the Windows Time service
net stop w32time
net start w32time

# Force Immediate Synchronization
w32tm /resync

#: View Synchronization Status and Configuration Source
w32tm /query /status
w32tm /query /source

Graphical Interface Configuration Methods

  1. Open Windows "Settings"
  2. Enter “Time and Language” -> "Date and Time"
  3. Found “Other Clocks” or “Internet Time” Settings
  4. Click "Change Settings" and check the box next to "Synchronize with an Internet time server."
  5. Enter the server as:ntp.bdtime.cn
  6. Click "Update Now," then click OK.

Open the “Terminal” app and run the following command:

# Configuring a Network Time Server
sudo systemsetup -setnetworktimeserver ntp.bdtime.cn

# Enable Network Time Synchronization
sudo systemsetup -setusingnetworktime on

# View the currently active network time server
systemsetup -getnetworktimeserver

Most network and smart devices support a graphical Web configuration interface. The typical path is:
System Settings -> Time Settings / Date and Time -> NTP Settings / SNTP Settings

Enter the NTP server address:

ntp.bdtime.cn

If the device only supports entering an IP address:

61.149.15.93

Note: Ports are typically left at their default settings (UDP 123).

Best Practices: Configuring Multiple Time Sources

For servers that run continuously or critical business systems, it is recommended to configure at least 2 to 4 NTP time sources to improve disaster recovery and availability.

server ntp.bdtime.cn iburst
server pool.ntp.org iburst
server time.cloudflare.com iburst
server time.google.com iburst

Service Boundaries and Usage Guidelines

To ensure that the public NTP service continues to benefit a wide range of users in the long term, please use this node in a reasonable and proper manner:

  • Please do not make high-frequency, abnormal, or malicious requests, and do not use this service for stress testing, scanning, or malicious traffic testing.
  • If you need to preconfigure default NTP addresses for bulk devices, firmware, or commercial products, we recommend contacting us in advance to assess capacity.
  • This node is a free, public service and does not provide commercial SLAs for all use cases.
  • For industrial, financial, and measurement applications that require extremely high time accuracy (at the microsecond/nanosecond level), it is recommended to deploy on-premises GNSS, PTP, or dedicated time synchronization hardware.

Frequently Asked Questions (FAQ)

Have questions while using the product? Check here for answers.

Yes. ntp.bdtime.cn is a free, public NTP time synchronization service provided by BDTIME for Internet users.
We recommend using a domain name whenever possible ntp.bdtime.cn. Domain names make it easier to maintain services and migrate nodes (via DNS round-robin) in the future. If your device does not support domain name configuration and you can only enter a numeric IP address, you can use 61.149.15.93The
NTP uses the following by default UDP 123 Ports. If the device is unable to complete synchronization, first check whether the firewall, security group, routing policies, or carrier network are restricting outbound access on UDP port 123.
No. The NTP protocol is only responsible for synchronization. UTC Time Reference(Ensure the system time is accurate.) The display of local time (such as Beijing Time, Eastern Time, and other time zone offsets and daylight saving time adjustments) is controlled separately by your operating system or application.
Most NTP clients automatically adjust the synchronization frequency based on the current offset, network conditions, and the stability of the local clock; they do not operate at a fixed, single interval. Typically, time synchronization occurs more frequently when the system first starts up or when the offset is significant, and the synchronization interval gradually increases once stability is achieved.
Please check the following common causes one by one:
  • Network Interception:Blocked by a firewall, security group, router ACL, or ISP UDP 123 Outbound access to the port.
  • Service not started:The service responsible for NTP in the system (such as chronyd, ntpd, or Windows Time) is not running.
  • Initial deviation is too large:If the local time differs from standard time by several years, some clients will refuse to perform an automatic time adjustment, requiring manual intervention. date or ntpdate Force a recalibration once.
  • Virtual Machine Overlay:The guest OS clock in a virtual machine may be overwritten by the underlying host OS's time synchronization tool, causing the configuration to fail.
  • Time zone error:The synchronization was actually successful, but due to an incorrect time zone setting on the device (for example, it was set to UTC, which made it appear to be 8 hours behind Beijing Time).
Yes. Most routers, switches, firewalls, cameras, NVRs, NAS devices, industrial controllers, and IoT devices support configuring an NTP server. Typically, you just need to enter the settings in the “Time Settings / Date and Time / NTP Settings” section of the device’s management interface. ntp.bdtime.cn, If the device does not support domain names, you can enter 61.149.15.93The
For small-scale, general-purpose use cases, you can usually configure this directly; however, if you plan to include this address by default in commercial devices, firmware, large-scale software platforms, or mass-produced products, we recommend contacting us in advance to assess capacity and usage patterns, in order to avoid placing concentrated strain on public and non-profit nodes.

Service Status Check

If you have finished the configuration but are unsure whether synchronization was actually successful, you can use the following command to quickly check the current time source, offset, and connectivity.

Linux / macOS 

# chrony: View Time Sources and Tracking Status
chronyc sources -v
chronyc tracking

#: Directly query the remote NTP response (available on some systems)
ntpdate -q ntp.bdtime.cn

Windows 

# View Current Sync Status
w32tm /query /status

# View the currently active time source
w32tm /query /source

# Connectivity and Biased Sampling
w32tm /stripchart /computer:ntp.bdtime.cn /samples:5 /dataonly

Quickly Check Connectivity

Run the following command in the terminal. If time-of-flight data is returned, it means your network can access the service normally:

# Windows Detection Commands:
w32tm /stripchart /computer:ntp.bdtime.cn /samples:5 /dataonly

# Linux/macOS: Testing with chrony or ntpdate...

Contact

If you encounter any issues while using ntp.bdtime.cn, or if you would like to integrate our NTP address in bulk into commercial devices, firmware, or large-scale software platforms, please feel free to contact us.

info@bdpnt.com

© BDTIME Public NTP Service. All rights reserved.

Building a Stable and Trustworthy Foundation for Internet Time

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