This example, for example, produces the output, "Fri Feb 13 15:26:30 EST 2009"

This command displays a clock on your terminal which updates the time every second. Press Ctrl-C to exit. A couple of variants: A little bit bigger text: watch -t -n1 "date +%T|figlet -f big" You can try other figlet fonts, too. Big sideways characters: watch -n 1 -t '/usr/games/banner -w 30 $(date +%M:%S)' This requires a particular version of banner and a 40-line terminal or you can adjust the width ("30" here). Show Sample Output

If you have used bash for any scripting, you've used the date command alot. It's perfect for using as a way to create filename's dynamically within aliases,functions, and commands like below.. This is actually an update to my first alias, since a few commenters (below) had good observations on what was wrong with my first command. # creating a date-based ssh-key for askapache.github.com ssh-keygen -f ~/.ssh/`date +git-$USER@$HOSTNAME-%m-%d-%g` -C 'webmaster@askapache.com' # /home/gpl/.ssh/git-gplnet@askapache.github.com-04-22-10 # create a tar+gzip backup of the current directory tar -czf $(date +$HOME/.backups/%m-%d-%g-%R-`sed -u 's/\//#/g' <<< $PWD`.tgz) . # tar -czf /home/gpl/.backups/04-22-10-01:13-#home#gpl#.rr#src.tgz . I personally find myself having to reference date --help quite a bit as a result. So this nice alias saves me a lot of time. This is one bdash mofo. Works in sh and bash (posix), but will likely need to be changed for other shells due to the parameter substitution going on.. Just extend the sed command, I prefer sed to pretty much everything anyways.. but it's always preferable to put in the extra effort to go for as much builtin use as you can. Otherwise it's not a top one-liner, it's a lazyboy recliner. Here's the old version: alias dateh='date --help|sed "/^ *%%/,/^ *%Z/!d;s/ \+/ /g"|while read l;do date "+ %${l/% */}_${l/% */}_${l#* }";done|column -s_ -t' This trick from my [ http://www.askapache.com/linux-unix/bash_profile-functions-advanced-shell.html bash_profile ] Show Sample Output

Not perl but shorter.

That works in all softs, CLI or GUI... I don't want to waste time to all the time typing the same stuff . So, I have that command in my window manager shortcuts ( meta+l ). All the window managers have editable shortcuts AFAIK. If not, or you don't want to use it that way, you can easily use the xbindkeys soft. I you're using kde4, you can run : systemsettings then open "inputs actions" and create a new shortcut. For Gnome take a look there : http://www.cyberciti.biz/faq/howto-create-keyboard-shortcuts-in-gnome/ A more advanced one, with strings and newlines : xvkbd -xsendevent -text "---8<-----\nToday date is: $(date +%Y%m%d)\n---8<-----" For complicated or long paste, you can feed xvkbd with a file : xvkbd -xsendevent -file <file> You can simulate ^C ( control+c ) too or others combinations of keys : xvkbd -text "\C\Ac" There's no man page nor help ( On my Archlinux distro ), but you can see online doc there : http://homepage3.nifty.com/tsato/xvkbd/ Show Sample Output

Not a discovery but a useful one nontheless. In the above example date format is 'yyyymmdd'. For other possible formats see 'man date'. This command can be also very convenient when aliased to some meaningful name: alias mkdd='mkdir $(date +%Y%m%d)'

Countdown clock - Counts down from $MIN minutes to zero. I let the date command do the maths. This version doesn't use seq. Show Sample Output

The British Government entering in the Gregorian era. Show Sample Output

Use `zless` to read the content of your *rss.gz file: zless commandlinefu-contribs-backup-2009-08-10-07.40.39.rss.gz Show Sample Output

Will edit *.db files in the same directory with todays date. Useful for doing a mass update to domains on a nameserver, adding spf records, etc. Looks for a string starting with 200 or 201 followed by 7 numbers, and replaces with todays date. This won't overwrite Ip's but i would still do some double checking after running this. Make sure your server's date is correct, otherwise insert your own serial number. rndc reload should usually follow this command.

You will see it on the corner of your running terminal. Show Sample Output

This script creates date based backups of the files. It copies the files to the same place the original ones are but with an additional extension that is the timestamp of the copy on the following format: YearMonthDay-HourMinuteSecond Show Sample Output

Uses date to grep de logfile for today and uses it to get the last hour logs. Can be used to get last minute logs or today's logs. Show Sample Output

This is useful when watching a log file that does not contain timestamps itself. If the file already has content when starting the command, the first lines will have the "wrong" timestamp when the command was started and not when the lines were originally written.

date -ud @1320198157

Shows a simple clock in the console -t param removes the watch header Ctrl-c to exit Show Sample Output

I removed the dependency of the English language Show Sample Output

More recent versions of the date command finally have the ability to decode the unix epoch time into a human readable date. This function makes it simple to utilize this feature quickly. Show Sample Output

This command prints the Date (Not time) from 3 days ago (72 hours ago). This works on systems without GNU date (MacOSX , Solaris, FreeBSD). Show Sample Output

Should be a bit more portable since echo -e/n and date's -Ins are not. Show Sample Output

Like 7171, but fixed typo, uses fewer variables, and even more cryptic! Show Sample Output

Create a file with actual date as filename Show Sample Output

displays current time in "binary clock" format (loosely) inspired by: http://www.thinkgeek.com/homeoffice/lights/59e0/ "Decoding": 8421 .... - 1st hour digit: 0 *..* - 2nd hour digit: 9 (8+1) .*.. - 1st minutes digit: 4 *..* - 2nd minutes digit: 9 (8+1) Prompt-command version: PROMPT_COMMAND='echo "10 i 2 o $(date +"%H%M"|cut -b 1,2,3,4 --output-delimiter=" ") f"|dc|tac|xargs printf "%04d\n"|tr "01" ".*"' Show Sample Output