Command: date

Print the system date and time.

date
date -u
date '+%Y-%m-%d %H:%M:%S %Z'

Use it when you need the machine’s idea of now. Use date -u when you need UTC.

How To Read It

The output includes a date, time, and timezone abbreviation. Logs, HTTP headers, cron, systemd timers, and git commits can use different timezone assumptions. For this course, course dates are local to Asia/Singapore.

Common Failures

• Time looks wrong: compare date and date -u before assuming the server clock is wrong.
• Scheduled work ran at a surprising time: check the timezone used by cron or systemd.
• HTTP Date header differs from local time: HTTP dates are commonly GMT.

Docs Pointers

• Run man date, then read -u and format examples.
• Read Time Zones.