Question

I need to create a bash shell script starting with a day and then loop through each subsequent day formatting that output as %Y_%m_d

I figure I can submit a start day and then another param for the number of days.

My issue/question is how to set a DATE (that is not now) and then add a day.

so my input would be 2010_04_01 6

my output would be

2010_04_01
2010_04_02
2010_04_03
2010_04_04
2010_04_05
2010_04_06

Answer 1

[radical@home ~]$ cat a.sh 
#!/bin/bash

START=`echo $1 | tr -d _`;

for (( c=0; c<$2; c++ ))
do
    echo -n "`date --date="$START +$c day" +%Y_%m_%d` ";
done

Now if you call this script with your params it will return what you wanted:

[radical@home ~]$ ./a.sh 2010_04_01 6
2010_04_01 2010_04_02 2010_04_03 2010_04_04 2010_04_05 2010_04_06