[SOLVED] how to get the days from a certain date?

snowball0916 · 12-11-2010, 08:55 PM

Hi, guys
Do you have any idea of calculating days' distance？

for instance,

Code:

( 2010-9-16 ) minus (2010-9-1) = 16 days

I have read the date manual, but I can't find any help from there.
Could you kindly help?
Thanks,
Milo

barriehie · 12-11-2010, 09:16 PM

This should get you started:

Code:

declare -i $day_of_the_year=$(date -d 'yyyy-mm-dd' +%j)

snowball0916 · 12-11-2010, 09:33 PM

Quote:

Originally Posted by barriehie

This should get you started:

Code:

declare -i $day_of_the_year=$(date -d 'yyyy-mm-dd' +%j)

hi, barriehie
Sorry, May be I am missing something on this problem:
Your solution works for current year.

But, this calculation is not always in current year,

Code:

[root@www ~]# declare -i day_of_the_year=$(date -d '1970-01-01' +%j)
[root@www ~]# echo $day_of_the_year
1

any idea?

Thanks,
br,
milo

speck · 12-12-2010, 01:40 AM

If you only want to use shell script (not Perl), then the following should work. Just pass the two dates on the command line.

Code:

./script.sh 2010-12-9 2010-10-3

Code:

#!/bin/sh

SECS_PER_DAY=86400

DATE1=`date -d $1 +%s`
DATE2=`date -d $2 +%s`

DIFF=$((($DATE1-$DATE2)/$SECS_PER_DAY))

echo $DIFF

snowball0916 · 12-12-2010, 01:47 AM

Quote:

Originally Posted by speck

If you only want to use shell script (not Perl), then the following should work. Just pass the two dates on the command line.

Code:

./script.sh 2010-12-9 2010-10-3

Code:

#!/bin/sh

SECS_PER_DAY=86400

DATE1=`date -d $1 +%s`
DATE2=`date -d $2 +%s`

DIFF=$((($DATE1-$DATE2)/$SECS_PER_DAY))

echo $DIFF

Thanks speck. It's so cool.