How to set the system time using the Linux date command

How to set the system time using the date command in Linux

Name: Date

Permission: All Users

Usage:

Date [-u] [-D datestr] [-s datestr] [-- UTC] [-- Universal]
[-- Date = datestr] [-- set = datestr] [-- help] [-- version] [+ format]
[Mmddhhmm [[CC] YY] [. SS]

Note:

Date can be used to display or set the date and time of the system. In terms of display, you can set the format to be displayed. The format is set to a plus sign followed by several tags, the available tags are listed as follows:

Time:

%: Print %

% N: Next row

% T: Skip

% H: hour (00 .. 23)

% I: hour (01 .. 12)

% K: hour (0 .. 23)

% L: hour (1 .. 12)

% M: minute (00 .. 59)

% P: displays local am or PM

% R: direct display time (in 12-hour format: hh: mm: ss [AP] m)

% S: the number of seconds since January 1, 1970 00:00:00 UTC till now

% S: seconds (00 .. 61)

% T: direct display time (in 24-hour format)

% X: equivalent to % H: % m: % s

% Z: display the time zone

Date:

% A: The day of the week (Sun .. SAT)

% A: The day of the week (Sunday .. Saturday)

% B: Month (Jan .. dec)

% B: Month (January... December)

% C: Display date and time directly

% D: Day (01 .. 31)

% D: Display date directly (mm/DD/yy)

% H: Same as % B

% J: The day of the year (001 .. 366)

% M: Month (01 .. 12)

% U: Week (00 .. 53) of the year (the first day of the week on Sunday)

% W: The day of the week (0 .. 6)

% W: Week (00 .. 53) of the Year (Monday is the first day of the week)

% X: Display date directly (mm/DD/yy)

% Y: last two digits of the Year (00.99)

% Y: full year (0000 .. 9999)

If it does not start with a plus sign, the time is set, and the time format is mmddhhmm [[CC] YY] [. SS], where mm is the month, DD is the day, HH is the hour, mm is the minute, CC is the first two digits of the Year, YY is the second digit of the Year, SS is the second digit

Parameters:

-D datestr: display the time set in datestr (non-system time)

-- Help: displays auxiliary messages.

-S datestr: set the system time to the time set in datestr

-U: displays the current Greenwich Mean Time.

-- Version: displays the version number.

Example:

After the time is displayed, the line jumps and the current date is displayed:

Date' + % T % N % d'

Show month and number of days:

Date' + % B % d'

Display date and set time (12:34:56 ):

Date -- date '12: 34: 56'

Note:

If you do not want meaningless 0 values (such as), you can insert a-symbol in the tag, such as date.
'+ %-H: %-M: %-S' will remove the meaningless 0 in the hour, as if the original 08:09:04 will change. In addition, only those who have the permission (for example
Root) to set the system time.

After you change the system time as root, remember to write the system time to CMOS using clock-w, in this way, the system time will continue to hold the latest correct value upon the next reboot.

Example: Modify the date and time

On the command line, enter:

Date

Show current time Fri Aug 3 14:15:16 CST 2007

Date-S

Modified by string

You can modify only the date without changing the time. Enter: Date-S

Modify the time only. Enter date-s 14:15:00.

Modify the date and time at the same time. Note that double quotation marks are required. There is a space between the date and time. Enter date-s "14:15:00"

After modification, enter clock-w.

Write System Time to CMOS