Get the date (a day before current time) in Bash

How can I print the date which is a day before current t开发者_StackOverflowime in Bash?

if you have GNU date and i understood you correctly

$ date +%Y:%m:%d -d "yesterday"
2009:11:09

or

$ date +%Y:%m:%d -d "1 day ago"
2009:11:09

If you have BSD (OSX) date you can do it like this:

date -j -v-1d
Wed Dec 14 15:34:14 CET 2011

Or if you want to do date calculations on an arbitrary date:

date -j -v-1d -f "%Y-%m-%d" "2011-09-01" "+%Y-%m-%d"
2011-08-31

date --date='-1 day'

MAC OSX

For yesterday's date:

date -v-1d +%F

where 1d defines current day minus 1 day. Similarly,

date -v-1w +%F - for previous week date

date -v-1m +%F - for previous month date

IF YOU HAVE GNU DATE,

date --date="1 day ago"

More info: https://www.cyberciti.biz/tips/linux-unix-get-yesterdays-tomorrows-date.html

Well this is a late answer,but this seems to work!!

     YESTERDAY=`TZ=GMT+24 date +%d-%m-%Y`;
     echo $YESTERDAY;

Advanced Bash-scripting Guide

date +%Y:%m:%d -d "yesterday"

For details about the date format see the man page for date

date --date='-1 day'

Sorry not mentioning I on Solaris system. As such, the -date switch is not available on Solaris bash.

I find out I can get the previous date with little trick on timezone.

DATE=`TZ=MYT+16 date +%Y-%m-%d_%r`
echo $DATE

date -d "yesterday" '+%Y-%m-%d'

or

date=$(date -d "yesterday" '+%Y-%m-%d')
echo $date

Use Perl instead perhaps?

perl -e 'print scalar localtime( time - 86400 ) . "\n";'

Or, use nawk and (ab)use /usr/bin/adb:

nawk 'BEGIN{printf "0t%d=Y\n", srand()-86400}' | adb

Came across this too ... insane!

/usr/bin/truss /usr/bin/date 2>&1 | nawk -F= '/^time\(\)/ {gsub(/ /,"",$2);printf "0t%d=Y\n", $2-86400}' | adb

date --date='-1 day'

Not very sexy but might do the job:

perl -e 'my ($sec,$min,$hour,$mday,$mon,$year,$wday,$yday,$isdst) = localtime(time - 86400);$year += 1900; $mon+= 1; printf ("YESTERDAY: %04d%02d%02d \n", $year, $mon, $mday)'

Formated from "martin clayton" answer.

You could do a simple calculation, pimped with an regex, if the chosen date format is 'YYYYMM':

echo $(($(date +"%Y%m") - 1)) | sed -e 's/99$/12/'

In January of 2020 it will return 201912 ;-) But, it's only a workaround, when date does not have calculation options and other dateinterpreter options (e.g. using perl) not available ;-)

if you are using OSX, but you need create for GNU compatible, first install coreutils

brew install coreutils

then edit your profile with:

#gnu coreutils first
export PATH="/usr/local/opt/coreutils/libexec/gnubin:$PATH"

re-start your terminal, and now you able to use GNU format:

date +%Y-%m-%d -d "-2 day"

yesterday=`date -d "-1 day" %F`

Puts yesterday's date in YYYY-MM-DD format into variable $yesterday.

#!/bin/bash
OFFSET=1;
eval `date "+day=%d; month=%m; year=%Y"`
# Subtract offset from day, if it goes below one use 'cal'
# to determine the number of days in the previous month.
day=`expr $day - $OFFSET`
if [ $day -le 0 ] ;then
month=`expr $month - 1`
if [ $month -eq 0 ] ;then
year=`expr $year - 1`
month=12
fi
set `cal $month $year`
xday=${$#}
day=`expr $xday + $day`
fi
echo $year-$month-$day

DST aware solution:

Manipulating the Timezone is possible for changing the clock some hours. Due to the daylight saving time, 24 hours ago can be today or the day before yesterday.

You are sure that yesterday is 20 or 30 hours ago. Which one? Well, the most recent one that is not today.

echo -e "$(TZ=GMT+30 date +%Y-%m-%d)\n$(TZ=GMT+20 date +%Y-%m-%d)" | grep -v $(date +%Y-%m-%d) | tail -1

The -e parameter used in the echo command is needed with bash, but will not work with ksh. In ksh you can use the same command without the -e flag.

When your script will be used in different environments, you can start the script with #!/bin/ksh or #!/bin/bash. You could also replace the \n by a newline:

echo "$(TZ=GMT+30 date +%Y-%m-%d)
$(TZ=GMT+20 date +%Y-%m-%d)" | grep -v $(date +%Y-%m-%d) | tail -1

Try the below code , which takes care of the DST part as well.

if [ $(date +%w) -eq $(date -u +%w) ]; then
  tz=$(( 10#$gmthour - 10#$localhour ))
else
  tz=$(( 24 - 10#$gmthour + 10#$localhour ))
fi
echo $tz
myTime=`TZ=GMT+$tz date +'%Y%m%d'`

Courtsey Ansgar Wiechers

date +%Y:%m:%d|awk -vFS=":" -vOFS=":" '{$3=$3-1;print}'
2009:11:9