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How to Fix Incorrect Time on a Linux VPS (Ubuntu, Debian, CentOS, AlmaLinux) 列印本文
How to Fix Incorrect Time on a Linux VPS (Ubuntu, Debian, CentOS & AlmaLinux)
Incorrect server time can cause SSL errors, cron job failures, email delivery problems, incorrect logs, and authentication issues. In this guide, we will show you how to check, fix, and synchronize time on Linux VPS servers.
Why VPS Time Synchronization Matters
Incorrect VPS time may cause:
- SSL certificate validation errors
- Broken cron jobs
- Email sending problems
- Incorrect server logs
- Database synchronization issues
- Authentication failures
For stable server operation, every VPS should have proper NTP time synchronization enabled.
Step 1 — Check Current VPS Time
Run the following command:
timedatectl
Example output:
Local time: Wed 2026-05-13 21:35:11 UTC
Universal time: Wed 2026-05-13 21:35:11 UTC
RTC time: Wed 2026-05-13 21:35:10
Time zone: UTC (UTC, +0000)
System clock synchronized: yes
NTP service: active
The important values are:
System clock synchronized: yes
NTP service: active
Step 2 — Set the Correct Timezone
Timezone controls how time is displayed on the server. Most VPS servers use UTC timezone by default.
To list available timezones:
timedatectl list-timezones
Example: Set timezone to Singapore
sudo timedatectl set-timezone Asia/Singapore
Example: Set timezone to New York
sudo timedatectl set-timezone America/New_York
Verify changes:
timedatectl
Ubuntu & Debian Time Synchronization
Ubuntu and Debian use systemd-timesyncd by default.
Enable Automatic Time Synchronization
sudo timedatectl set-ntp true
Restart the synchronization service:
sudo systemctl restart systemd-timesyncd
Verify synchronization status:
timedatectl status
Configure External NTP Servers (Ubuntu/Debian)
Edit the configuration file:
sudo nano /etc/systemd/timesyncd.conf
Add the following:
[Time]
NTP=time.google.com time.cloudflare.com pool.ntp.org
FallbackNTP=ntp.ubuntu.com
Restart the service:
sudo systemctl restart systemd-timesyncd
Check synchronization:
timedatectl timesync-status
CentOS / AlmaLinux / Rocky Linux Time Synchronization
These operating systems commonly use Chrony for NTP synchronization.
Install Chrony
CentOS 7:
sudo yum install chrony -y
AlmaLinux / Rocky Linux:
sudo dnf install chrony -y
Enable and Start Chrony
sudo systemctl enable chronyd
sudo systemctl start chronyd
Check service status:
systemctl status chronyd
Configure External NTP Servers (Chrony)
Edit Chrony configuration:
sudo nano /etc/chrony.conf
Add the following servers:
server time.google.com iburst
server time.cloudflare.com iburst
server pool.ntp.org iburst
Restart Chrony:
sudo systemctl restart chronyd
Verify synchronization:
chronyc tracking
chronyc sources
Force Immediate Time Synchronization
If the VPS clock is heavily out of sync, restart the synchronization service.
Ubuntu / Debian
sudo systemctl restart systemd-timesyncd
CentOS / AlmaLinux / Rocky Linux
sudo systemctl restart chronyd
Verify:
timedatectl
Manual Time Adjustment (Temporary Fix)
Manual time changes should only be used temporarily.
sudo timedatectl set-time "2026-05-13 21:45:00"
Or:
sudo date -s "2026-05-13 21:45:00"
Once NTP synchronization resumes, the server will automatically correct itself.
Recommended Public NTP Servers
time.google.com
time.cloudflare.com
pool.ntp.org
ntp.ubuntu.com
Troubleshooting
NTP Service Not Active
sudo timedatectl set-ntp true
Or restart Chrony:
sudo systemctl restart chronyd
Firewall Blocking NTP
NTP uses UDP port 123.
sudo firewall-cmd --add-service=ntp --permanent
sudo firewall-cmd --reload
Final Notes
Correct server time is critical for stable VPS operation. We strongly recommend enabling automatic NTP synchronization on every Linux VPS immediately after deployment.
If your VPS continues experiencing time synchronization problems, contact your hosting provider for assistance.
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