April 1

I'm having trouble calculating a date of April 1 2002. 

Postgres 7.1.3 Linux 2.4.14

select date(date('2002-03-30') + interval('1 day'))

result 2002-03-31

select date(date('2002-03-31') + interval('1 day'))

result 2002-03-31

It seems as though the "+ interval('1 day'))" only adds 23 hours rather than 24.

So adding "interval( '1 day')" to the march 31 returns march 31.

It may have something to do with day light savings.

Can any one suggest a work around?

Is this a bug?

Thanks