how to add a day to date in bash?

Question

For example, I have date: 4 August 1993 and I want to add 348 days to it, how can I do it in bash?

Answer 1

Just use the date command with -d option:

$ date -d "1983-08-04 348 days"
Tue Jul 17 00:00:00 BST 1984  

You can change the output format if you want:

$ date -d "1983-08-04 2 days" +%Y-%m-%d
1983-08-06                                           

Answer 2

In bash on Mac OS X, you can do this:

date -j -v +348d -f "%Y-%m-%d" "1993-08-04" +%Y-%m-%d

Output: 1994-07-18

Answer 3

Here is a little more complex usage of this:

for i in `seq 1 5`;
do;
  date -d "2014-02-01 $i days" +%Y-%m-%d;
done;

or with pipes:

seq 1 5 | xargs -I {} date -d "2014-02-01 {} days" +%Y-%m-%d