原子時計の精度に同期された現在時刻。このページはデバイスの時計とUTCの差をリアルタイムで測定します — アプリやダウンロード不要。
UTC Time
2026-04-17T08:38:48.817Z
Your Local Time
--:--:--
2026-04-17 · Friday · Day 107 of 2026
UNIX: 0
Your Device
Sends time request via UDP port 123
NTP Pool
pool.ntp.org — 4,000+ distributed servers
Stratum 1
Directly connected to reference clock
Atomic Clock
Cesium / GPS — accurate to nanoseconds
Protocol
NTP v4 (RFC 5905)
Transport
UDP port 123
Typical accuracy
< 50ms over internet
| Platform | NTP Server | Protocol | Sync Interval | Manual Override Path |
|---|---|---|---|---|
| 🪟Windows 11 | time.windows.com | NTP / W32tm | Weekly | Settings → Time & Language → Date & Time |
| 🍎macOS | time.apple.com | NTP | Daily | System Settings → General → Date & Time |
| 📱iOS / iPadOS | time.apple.com | NTP | Automatic | Settings → General → Date & Time → Set Automatically |
| 🤖Android | time.android.com | NTP | Automatic | Settings → System → Date & Time |
| 🐧Ubuntu Linux | pool.ntp.org | systemd-timesyncd | On connect + periodic | /etc/systemd/timesyncd.conf |
| 🔵ChromeOS | time.google.com | NTP | Automatic | Settings → Advanced → Date & Time |
🪟Windows 11
NTP Server
time.windows.com
Protocol
NTP / W32tm
Sync Interval
Weekly
Manual Override
Settings → Time & Language → Date & Time
🍎macOS
NTP Server
time.apple.com
Protocol
NTP
Sync Interval
Daily
Manual Override
System Settings → General → Date & Time
📱iOS / iPadOS
NTP Server
time.apple.com
Protocol
NTP
Sync Interval
Automatic
Manual Override
Settings → General → Date & Time → Set Automatically
🤖Android
NTP Server
time.android.com
Protocol
NTP
Sync Interval
Automatic
Manual Override
Settings → System → Date & Time
🐧Ubuntu Linux
NTP Server
pool.ntp.org
Protocol
systemd-timesyncd
Sync Interval
On connect + periodic
Manual Override
/etc/systemd/timesyncd.conf
🔵ChromeOS
NTP Server
time.google.com
Protocol
NTP
Sync Interval
Automatic
Manual Override
Settings → Advanced → Date & Time