Every time you check the time on your phone, receive a timestamped email, or use two-factor authentication... NTP is working behind the scenes.
NTP stands for Network Time Protocol.
Imagine a giant speaking clock on the Internet. Your phone, your computer, your router... all these devices regularly ask it: "What time is it exactly?"
This "speaking clock" is actually a network of time servers synchronized to atomic clocks — the most accurate clocks in the world, which only drift by one second every 300 million years!
Good news (or bad, depending on your perspective): you don't have to do anything! NTP works automatically on virtually all your connected devices.
Automatically synchronized via Google servers or your carrier
Uses Apple servers (time.apple.com) automatically
"Windows Time" service enabled by default (time.windows.com)
Synchronized via Apple servers automatically
Uses chrony, systemd-timesyncd, or ntpd depending on the distribution
Automatic time setting via Internet or broadcast signal
Synchronized to your ISP's servers
GPS satellites also transmit atomic time
Imagine you want to know the exact time. You have 3 watches, but they don't all show quite the same time:
What do you do? Instinctively, you trust the majority. Two watches show ~2:02 PM, so that's probably the correct time.
NTP works exactly the same way! Your device queries multiple time servers, compares their responses, eliminates outliers, and calculates the best estimate of the actual time. This is called Marzullo's algorithm.
The NTP protocol is organized into hierarchical levels called "Stratum":
NTS stands for Network Time Security. It is an evolution of NTP that adds a cryptographic security layer.
Like a postcard
Like a sealed registered letter
Learn more about NTS and how to enable it →
A pool is a group of time servers that work together. Instead of relying on a single server (which could go down), your device can query multiple servers in the pool.
The most well-known is ntppool.org: over 4,000 servers worldwide, including ~370 in France.
| Provider | Address | Specifics |
|---|---|---|
| Global NTP Pool | pool.ntp.org | Community-run, 4000+ servers |
| France NTP Pool | fr.pool.ntp.org | ~370 French servers |
| time.google.com | Leap smearing (smooth leap second handling) | |
| Cloudflare | time.cloudflare.com | Supports NTS |
| Apple | time.apple.com | Used by iOS/macOS |
| RDEM Systems | ntp-pool.rdem-systems.com | 11 servers, NTS enabled, France |
You don't have to do anything! Your devices are already configured. NTP ensures that your emails arrive with the correct timestamp, that your 2FA codes work, and that your photos are correctly dated.
Consistent time is crucial for:
Industrial systems (SCADA, PLCs) require precise synchronization to coordinate manufacturing processes and ensure traceability.
Financial markets require microsecond-level timestamping. MiFID II mandates 100-microsecond accuracy for high-frequency trading.
Imagine an orchestra where each musician had their own clock, slightly off. The result would be cacophony!
In the IT world, it's the same: without time synchronization, systems cannot collaborate effectively. Emails arrive "before" they were sent, backups overwrite newer files, logs become incomprehensible...
Is your device properly synchronized? Test it with one click!
Check my clockDiscover our NTP infrastructure | Enable NTS (secure) | Our Stratum 1 server