Linux system Time

Command-line mode
Date: Displays the current time
Date +%s: Display timestamp

Date command:
The general format is: Date [options] display time format (start with +, followed by format)

Option parameters:
-d< string > Displays the date and time that the string refers to (the string must be quoted)
-s< string > Set date and Time based on string (string must be quoted)-----only root permission can
--help online Help
--version displaying version information

List of date format character strings:
%H: Hours (00..23)
%I: Hours (01..12)
%k: Hours (0..23)
%l: Hours (1..12)
%M: minutes (00..59)
%p: Show local AM or PM
%r: Direct Display time (12 hours, Format hh:mm:ss [ap]m)
%s: The number of seconds from January 1, 1970 00:00:00 UTC to the current date
%s: Seconds (00..61)
%T: Direct Display time (24-hour system) (HH:MM:SS)
%x: Format of the display time (%h:%m:%s)
%Z: Show Time zone
% A: Abbreviation for the day of the week (Sun. Sat)
% A: The full name of the day of the week (Sunday. Saturday)
%B: The month abbreviation (Jan. DEC)
%B: Month full name (January. December)
%c: Display date and time directly
%d: Day (01..31)
%d: direct display?? Period (MM/DD/YY)
%h: With%b
%j: The first day of the Year (001..366)
%m: Month (01..12)
%u: Week of the Year (00..53) (with Sunday as the day of the week)
%w: The day of the Week (0..6)
%W: The week of the Year (00..53) (in the case of Monday for the first few weeks)
%x: Show date directly (MM/DD/YY)
%y: Last two digits of the year (00.99)
%Y: Full year (0000..9999)

Several common combinations of parameters:
%Y: Full year (0000..9999)
%m: Month (01..12)%x,%d: Show date directly (MM/DD/YY)
%d: Day (01..31)

%H: Hours (00..23)
%M: Minutes (00..59)%T: Direct Display time (24-hour system)
%s: Seconds (00..61)%x: equivalent to%h:%m:%s

%c: Display date and time directly
Example:
[[Email protected] Desktop]# date +%y-%m-%d/%h:%m:%s
2018-03-30/09:29:53
[[Email protected] Desktop]# date +%x/%h:%m:%s
March 30, 2018/09:30:08
[[Email protected] Desktop]# date +%d/%h:%m:%s
03/30/18/09:35:48
[[Email protected] Desktop]# date +%x/%t
March 30, 2018/09:30:18
[[Email protected] Desktop]# date +%x/%x
March 30, 2018/09 30 minutes 26 seconds
[[Email protected] Desktop]# date +%c
March 30, 2018 Friday 09:38 37 seconds

The date command itself provides the addition and subtraction of dates

Date +%y%m%d//show current Month day
Date +%y%m%d--date= "+1 Day"//Display days later
Date +%y%m%d--date= "-1 days"//Displays the day before
Date +%y%m%d--date= "-1 month"//show dates on January
Date +%y%m%d--date= "+1 Month"//displays the dates for the next January
Date +%y%m%d--date= "-1 Year"//show dates for previous years
Date +%y%m%d--date= "+1 Year"//show dates for next

Example:
[[Email protected] Desktop]# date +%y%m%d
20180330
[[Email protected] Desktop]# date +%y%m%d--date= "+1 Day"
20180331
[[Email protected] Desktop]# date +%y%m%d--date= "-1 day"
20180329
[[Email protected] Desktop]# date +%y%m%d--date= "+1 Month"
20180430
[[Email protected] Desktop]# date +%y%m%d--date= "-1 month"
20180302
[[Email protected] Desktop]# date +%y%m%d--date= "+1 Year"
20190330
[[Email protected] Desktop]# date +%y%m%d--date= "-1 year"
20170330

Time stamp
Time, time stamp: Date +%s
Time stamp, time: Date +%y:%m:%d-d @1425384141

Example:
[[Email protected] Desktop]# date +%s
1522372436
[Email protected] Desktop]# date +%y-%m-%d/%h:%m:%s [email protected]
2018-03-30/09:13:56

Linux system Time