bug in "date" ?

[Manuel de la Torre Juárez]

Hi,

date (from GNU sh-utils 2.0 Release 50) seems to be skipping one hour at
the beginning of April 2001 on
my DELL Inspiron 8100:

I just made the following test:  
    > date --date="2001-04-01 00:00" +%s 
    986112000
    > date --date="2001-04-01 23:00" +%s 
    986191200
    > date --date="2001-04-02 00:00" +%s
    986194800
    >echo '(986194800-986112000)/3600' | bc -l
    23.00000000000000000000
That is, Apr 1st of 2001 seems to have had only 23 hours (April fools
day !)

If I try the alternative, which is 
   > date -d 2001-04-01 +%s
   986112000
   > date -d 2001-04-02 +%s
   986194800

Let us add now 23 hours to the first result of date -d:
   > echo '23*3600 + 986112000' |bc -l
   986194800 

But this is precisely the same number as would be obtained for 
date -d 2001-04-02 +%s ---> 1 hour is missing.
This 1 hour offset seems persistent until 2001-10-29 when it is
disappears.

Any reason for that ?
Manuel de la Torre.

P.S. If the same exercise is repeated  for a day previous to 2001-04-01
or after 2001-10-29, date returns consistent values. For example,
repeating the previous commands
for 2001-02-01, and 2001-02-02 does not produce the same type of
inconsistency.
   > date -d 2001-02-02 +%s
   981100800
   > echo "23*3600 + `date -d 2001-02-01 +%s`" | bc -l
   981097200
both numbers differ now by 3600 seconds as is expected

The problem does not occur for 2002.