date

Set or display the system date. More information: https://keith.github.io/xcode-man-pages/date.1.html.

Display the current date using the default locale's format:

date +%c

Display the current date in UTC and ISO 8601 format:

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

Display the current date as a Unix timestamp (seconds since the Unix epoch):

date +%s

Display a specific date (represented as a Unix timestamp) using the default format:

date -r {{1473305798}}