date—displays the date and time or sets the date
date [-u] [-d datestr] [-s datestr] [--utc][--universal] [--date=datestr] [--set=datestr] [--help][--version] [+FORMAT] [MMDDhhmm[[CC]YY][.ss]]
Without arguments, the date command displays the date and time. If the command line argument starts with a plus sign, the rest of the argument is used to format the output. If a percent sign is used, the next character is a formatting character to extract a particular part of the date, such as just the year or weekday. To set the date, the command line argument is expressed in digits representing the year, month, day, hours, and minutes.
1 date +%T 2 date +20%y 3 date "+It is now %m/%d /%y" 4 date --help
Displays the time ...