A bug exists in "date" build-in function?

[endeavor]

Hi All,

I tryied the following commands (see below) on several Linux kernels, it looks there are some bugs exist in date build-in function I am not sure about this, can anyone test the command on Fedora, I do not have Fedora available at the moment.
Thanks.


On PC cygwin


hzs@work
$ uname -a
CYGWIN_NT-5.1 work 1.5.25(0.156/4/2) 2008-06-12 19:34 i686 Cygwin

hzs@work
$ date -d "20071101 73 hours" +%Y-%m-%d_%H:00:00
2007-11-04_01:00:00

hzs@work
$ date -d "20071101 74 hours" +%Y-%m-%d_%H:00:00
2007-11-04_01:00:00

hzs@work
$ date -d "20071101 75 hours" +%Y-%m-%d_%H:00:00
2007-11-04_02:00:00


On CentOS


hzs@work1
$ uname -a
Linux work1 2.6.9-55.0.2.ELsmp #1 SMP Tue Jun 26 14:14:47 EDT 2007 x86_64 x86_64 x86_64 GNU/Linux

hzs@work1
$ date -d "20071101 73 hours" +%Y-%m-%d_%H:00:00
2007-11-04_01:00:00

hzs@work1
$ date -d "20071101 74 hours" +%Y-%m-%d_%H:00:00
2007-11-04_02:00:00

hzs@work1
$ date -d "20071101 75 hours" +%Y-%m-%d_%H:00:00
2007-11-04_03:00:00


Another CentOS different kernel

Linux work2 2.6.18-92.1.6.el5 #1 SMP Wed Jun 25 13:49:24 EDT 2008 i686 i686 i386 GNU/Linux

[1244][hzs@work2]$ date -d "20071101 73 hours" +%Y-%m-%d_%H:00:00
2007-11-04_01:00:00
[1244][hzs@work2]$ date -d "20071101 74 hours" +%Y-%m-%d_%H:00:00
2007-11-04_01:00:00
[1244][hzs@work2$ date -d "20071101 75 hours" +%Y-%m-%d_%H:00:00
2007-11-04_02:00:00

[leigh123linux]

[leigh05@localhost ~]$ uname -a
Linux localhost.leigh123.homelinux.com 2.6.26.6-71.fc9.x86_64 #1 SMP Mon Oct 13 17:38:08 EDT 2008 x86_64 x86_64 x86_64 GNU/Linux
[leigh05@localhost ~]$ date -d "20071101 73 hours" +%Y-%m-%d_%H:00:00
2007-11-04_01:00:00
[leigh05@localhost ~]$ date -d "20071101 74 hours" +%Y-%m-%d_%H:00:00
2007-11-04_02:00:00
[leigh05@localhost ~]$ date -d "20071101 75 hours" +%Y-%m-%d_%H:00:00
2007-11-04_03:00:00
[leigh05@localhost ~]$