date function working wrongly on last three days of march.

[shanrajan]

I am currently using date command to find the previous months from current month.

I ran this command in March 30, 2009

date --date="0 month ago" +%b
o/p: Mar

date --date="1 month ago" +%b
o/p: Mar

date --date="2 month ago" +%b

o/p : Jan

this command is working fine in every month except last three days of march.
For the first two commands the o/p is same. I think this is because of some wrong logic.

is there any fix available for this.

I am using redhat distro.
uname -a

Linux dbll1bil 2.4.21-4.EL #1 Sat Dec 13 21:37:48 CST 2003 i686 athlon i386 GNU/Linux

[blinky]

Can config it's there in Fedora 8 - using date (GNU coreutils) 6.9

Tried the OP's commands and
date --date="-1 month" +%b
date --date="-2 month" +%b

get the same results.

[lomcevak]

I had a similar problem but with --date="1 day ago". It was the day after the time changed in the US (at least for me in the East). It moved 1 hour forward. I think that that time change is causing GNU date problems.

Edit: Forgot to mention I'm using RHEL V4.7. Also, the problem was it gave me the date 2 days ago, not 1.

[lomcevak]

Well I did some research and found that this may not be a problem but intended behavior. Here's the link.

To solve your month problem using their solution the command to use is:

date --date="`date +%b` 15 1 month ago" +%b

Edit: Actually the above doesn't work. This does:

date --date="`date +%Y-%m`-15 1 month ago"