`date` - print or set the system date and time

date [+FORMAT] [-u]

Options you will use

+FORMAT: Format the output: %Y %m %d %H %M %S %F %T %s ...
-u, --utc: Print Coordinated Universal Time.
-d, --date STRING: Show the time described by STRING instead of now: -d "+19 days", -d yesterday, -d @1700000000.

$ date +%F

2026-09-23

$ date -u +"%Y-%m-%dT%H:%M:%SZ"

ISO 8601 timestamp

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