prints out the time for the timezone specified in $offsetutc. So you have less to think about things like: "I'm in utc+4 and my friend in utc-7, can I call him now or will I wake him?"

Note: $offsetutc should be an integer between -12 and 12.

It will create a backup of the filename. The advantage is that if you list the folder the backups will be sorted by date. The command works on any unix in bash.

A quick and simple way of outputting the start and end date of a certificate, you can simply use 'openssl x509 -in xxxxxx.crt -noout -enddate' to output the end date (ex. notAfter=Feb 01 11:30:32 2009 GMT) and with the date command you format the output to an ISO format.

For the start date use the switch -startdate and for end date use -enddate.

Performs a mysqldump and gzip-compresses the output file with a timestamp in the resulting dump file. Inspect the file for integrity or fun with this command afterward, if you desire:

With this command you can get a previous or future date or time. Where can you use this? How about finding all files modified or created in the last 5 mins?

touch -t `echo $(date -d "5 minute ago" "+%G%m%d%H%M.%S")` me && find . -type f -newer me

List all directories created since last week?

touch -t `echo $(date -d "1 week ago" "+%G%m%d%H%M.%S")` me && find . -type d -cnewer me

I'm sure you can think of more ways to use it. Requires coreutils package.

Important to know: a valid date will return 0, otherwise 1!

Use date to find the date at other days and times.

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:

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

creates a tar.gz with a name like:

backup20090410_173053.tar.gz

of a given directory.

this file was made 10 April 2009 at 5:30:53pm

see date's man page to customize the timestamp format

Echos the number of seconds from the current time till the specified time (Example in command is (2**31-1)) aka the Unix epoch. Just replace that number with the specified date (in seconds past Jan. 1st 1970) and it will return the seconds.

NOTE: Only works in bash

04/01/0902:11:42

Sys Temp: +11.0?C

CPU Temp: +35.5?C

AUX Temp: +3.0?C

http://en.wikipedia.org/wiki/Year_2038_problem

Some other notable dates that have passed:

I needed to get a feel for how "old" different websites were, based on their directories.

prerequisite:

Useful to archive files once a day:

Good for automating reports that need to run from between two dates.

On other systems, replace 'say' with the name of another text-to-speech engine, e.g. espeak ( http://espeak.sourceforge.net ) or festival ( http://www.cstr.ed.ac.uk/projects/festival )

Today

displays time in seconds since January 1, 1970 UTC

A useful bash function:

gztardir()

{

if [ $# -ne 1 ] ; then

echo "incorrect arguments: should be gztardir "

else

tar zcvf "${1%/}-$(date +%Y%m%d-%H%M).tar.gz" "$1"

fi

}