The jPC, by default, is configured to synchronize its real time clock (RTC) with an Internet time server any time it is connected to the Internet.

Should this feature become disabled, you can enable it with the following command:

sudo timedatectl set-ntp true

To manually set the date and time, first disable the Internet timer server synchronization:

sudo timedatectl set-ntp false

Then set the date and time manually:

sudo timedatectl set-time "2025-12-03 14:30:00"

To set the time zone run the following commands:

# Check current timezone
timedatectl
 
# List available timezones
timedatectl list-timezones
 
# Set your desired timezone (example: Asia/Seoul)
sudo timedatectl set-timezone Asia/Seoul
 
# Or for US Eastern Time
sudo timedatectl set-timezone America/New_York
 
# Verify it worked
timedatectl