Home » Linux: set date through command line

Linux: set date through command line

Solutons:


Use date -s:

date -s '2014-12-25 12:34:56'

Run that as root or under sudo. Changing only one of the year/month/day is more of a challenge and will involve repeating bits of the current date. There are also GUI date tools built in to the major desktop environments, usually accessed through the clock.

To change only part of the time, you can use command substitution in the date string:

date -s "2014-12-25 $(date +%H:%M:%S)"

will change the date, but keep the time. See man date for formatting details to construct other combinations: the individual components are %Y, %m, %d, %H, %M, and %S.

System time

You can use date to set the system date. The GNU implementation of date (as found on most non-embedded Linux-based systems) accepts many different formats to set the time, here a few examples:

set only the year:

date -s 'next year'
date -s 'last year'

set only the month:

date -s 'last month'
date -s 'next month'

set only the day:

date -s 'next day'
date -s 'tomorrow'
date -s 'last day'
date -s 'yesterday'
date -s 'friday'

set all together:

date -s '2009-02-13 11:31:30' #that's a magical timestamp

Hardware time

Now the system time is set, but you may want to sync it with the hardware clock:

Use --show to print the hardware time:

hwclock --show

You can set the hardware clock to the current system time:

hwclock --systohc

Or the system time to the hardware clock

hwclock --hctosys

The command to to change the system date is date.

There are two ways to call the date command(in Linux):

   date [OPTION]... [+FORMAT]
   date [-u|--utc|--universal] [MMDDhhmm[[CC]YY][.ss]]

Easy

The easiest way is to use date -s as it allows the use of simple relative dates

 $ date -s yesterday; date
 date: cannot set date: Operation not permitted
 Sat Jan  5 07:21:07 EST 2019
 Sun Jan  6 07:21:07 EST 2019

The date did not change because it was executed with a limited user $. If you actually want the date changed, use root (#) or sudo:

 $ sudo date -s yesterday; date
 Sat Jan  5 07:21:07 EST 2019
 Sat Jan  5 07:21:07 EST 2019

So, changing any part of a relative date is as easy as naming it:

 $ date -s "5 years ago"
 Mon Jan  6 08:26:26 EST 2014

 $ date -s "+6 months"
 Sat Jul  6 08:28:39 EDT 2019

 $ date -s "+3 hours -13 minutes"
 Sun Jan  6 11:16:59 AST 2019

Absolute dates are a bit more complex as they need more detail:

 $ date -s "2001-07-23 10:11:12"

Or, you can use the date command twice:

 $ date -s "$(date +'%Y-%m-%d %H:%M:%S')"

replace any of the % by a valid value and the date will be set (only as root).

 $ date -s "$(date +'%Y-11-%d %H:%M:%S')"
 Wed Nov  6 08:37:15 EST 2019

direct

The second date call form is used to directly change the system date.

 date [-u|--utc|--universal] [MMDDhhmm[[CC]YY][.ss]]

So :

 date 11230812              # MMDDhhmm

Will set the date to the 23th of November at 08h and 12min.

BSD has a similar command but a different format ([[[[[cc]yy]mm]dd]HH]MM[.ss]).

Try date as a limited user to see what it would do (without changing anything):

 $ date 11230812
 date: cannot set date: Operation not permitted
 Sat Nov 23 08:12:00 EST 2019

Or, if you actually want to change the date, as root:

 # date 11230812
 # date
 Sat Nov 23 08:12:00 EST 2019

Note that services like NTP or chrony will be affected. And, if restarted will reset the date back to the real one.

Add a YY to set the year:

 $ date 1123081222
 date: cannot set date: Operation not permitted
 Wed Nov 23 08:12:00 EST 2022

Or a CCYY to set year and century:

 $ date 112308121982
 date: cannot set date: Operation not permitted
 Tue Nov 23 08:12:00 EST 1982

Related Solutions

Joining bash arguments into single string with spaces

[*] I believe that this does what you want. It will put all the arguments in one string, separated by spaces, with single quotes around all: str="'$*'" $* produces all the scripts arguments separated by the first character of $IFS which, by default, is a space....

AddTransient, AddScoped and AddSingleton Services Differences

TL;DR Transient objects are always different; a new instance is provided to every controller and every service. Scoped objects are the same within a request, but different across different requests. Singleton objects are the same for every object and every...

How to download package not install it with apt-get command?

Use --download-only: sudo apt-get install --download-only pppoe This will download pppoe and any dependencies you need, and place them in /var/cache/apt/archives. That way a subsequent apt-get install pppoe will be able to complete without any extra downloads....

What defines the maximum size for a command single argument?

Answers Definitely not a bug. The parameter which defines the maximum size for one argument is MAX_ARG_STRLEN. There is no documentation for this parameter other than the comments in binfmts.h: /* * These are the maximum length and maximum number of strings...

Bulk rename, change prefix

I'd say the simplest it to just use the rename command which is common on many Linux distributions. There are two common versions of this command so check its man page to find which one you have: ## rename from Perl (common in Debian systems -- Ubuntu, Mint,...

Output from ls has newlines but displays on a single line. Why?

When you pipe the output, ls acts differently. This fact is hidden away in the info documentation: If standard output is a terminal, the output is in columns (sorted vertically) and control characters are output as question marks; otherwise, the output is...

mv: Move file only if destination does not exist

mv -vn file1 file2. This command will do what you want. You can skip -v if you want. -v makes it verbose - mv will tell you that it moved file if it moves it(useful, since there is possibility that file will not be moved) -n moves only if file2 does not exist....

Is it possible to store and query JSON in SQLite?

SQLite 3.9 introduced a new extension (JSON1) that allows you to easily work with JSON data . Also, it introduced support for indexes on expressions, which (in my understanding) should allow you to define indexes on your JSON data as well. PostgreSQL has some...

Combining tail && journalctl

You could use: journalctl -u service-name -f -f, --follow Show only the most recent journal entries, and continuously print new entries as they are appended to the journal. Here I've added "service-name" to distinguish this answer from others; you substitute...

how can shellshock be exploited over SSH?

One example where this can be exploited is on servers with an authorized_keys forced command. When adding an entry to ~/.ssh/authorized_keys, you can prefix the line with command="foo" to force foo to be run any time that ssh public key is used. With this...

Why doesn’t the tilde (~) expand inside double quotes?

The reason, because inside double quotes, tilde ~ has no special meaning, it's treated as literal. POSIX defines Double-Quotes as: Enclosing characters in double-quotes ( "" ) shall preserve the literal value of all characters within the double-quotes, with the...

What is GNU Info for?

GNU Info was designed to offer documentation that was comprehensive, hyperlinked, and possible to output to multiple formats. Man pages were available, and they were great at providing printed output. However, they were designed such that each man page had a...

Set systemd service to execute after fstab mount

a CIFS network location is mounted via /etc/fstab to /mnt/ on boot-up. No, it is not. Get this right, and the rest falls into place naturally. The mount is handled by a (generated) systemd mount unit that will be named something like mnt-wibble.mount. You can...

Merge two video clips into one, placing them next to each other

To be honest, using the accepted answer resulted in a lot of dropped frames for me. However, using the hstack filter_complex produced perfectly fluid output: ffmpeg -i left.mp4 -i right.mp4 -filter_complex hstack output.mp4 ffmpeg -i input1.mp4 -i input2.mp4...

How portable are /dev/stdin, /dev/stdout and /dev/stderr?

It's been available on Linux back into its prehistory. It is not POSIX, although many actual shells (including AT&T ksh and bash) will simulate it if it's not present in the OS; note that this simulation only works at the shell level (i.e. redirection or...

How can I increase the number of inodes in an ext4 filesystem?

It seems that you have a lot more files than normal expectation. I don't know whether there is a solution to change the inode table size dynamically. I'm afraid that you need to back-up your data, and create new filesystem, and restore your data. To create new...

Why doesn’t cp have a progress bar like wget?

The tradition in unix tools is to display messages only if something goes wrong. I think this is both for design and practical reasons. The design is intended to make it obvious when something goes wrong: you get an error message, and it's not drowned in...