date flags & options
+format
Display the date in a custom format using format specifiers.
date "+%Y-%m-%d"
date "+%Y-%m-%d %H:%M:%S"
date "+%A, %B %d, %Y"
-d, --date
Display a specific date string instead of the current time.
date -d "next Friday"
date -d "2 days ago" "+%Y-%m-%d"
date -d "2025-12-25" "+%A"
-u, --utc
Display or set the date in UTC instead of the local timezone.
date -u
date -u "+%H:%M:%S"
-r
Display the last modification time of a file.
date -r /etc/passwd
date -r app.log "+%Y-%m-%d %H:%M"
-I, --iso-8601
Output the date in ISO 8601 format.
date -I
date -Iseconds
date -Ins