Re: BUG #11883: Year 1500 not treated as leap year when it was a leap year - Mailing list pgsql-bugs

On Wed, Nov  5, 2014 at 05:56:07PM +0000, hunsakerbn@familysearch.org wrote:
> The following bug has been logged on the website:
>
> Bug reference:      11883
> Logged by:          Bruce Hunsaker
> Email address:      hunsakerbn@familysearch.org
> PostgreSQL version: 9.3.5
> Operating system:   Linux
> Description:
>
> Entering historical dates we found we could not enter a date of '1500-02-29'
> Even though 1500 is documented to be a leap year. Tested with date and
> timestamp column types.
>
> To reproduce:
>  psql> create table date_test (mydate date);
> CREATE TABLE
> psql> insert into date_test values ('1500-02-29');
> ERROR:  date/time field value out of range: "1500-02-29"
> LINE 1: insert into date_test values ('1500-02-29');
>
> psql> insert into date_test values ('1500-02-28');
> INSERT 0 1;
>
> So, Feb 29, is not allowed but Feb 28 is.

Uh, what makes you think 1500 was a leap year?  This is the canonical
way to calculate which years are leap years:

    #define isleap(y) (((y) % 4) == 0 && (((y) % 100) != 0 || ((y) % 400) == 0))

Because 1500 % 100 == 0, I think 1500 was not a leap year.

--
  Bruce Momjian  <bruce@momjian.us>        http://momjian.us
  EnterpriseDB                             http://enterprisedb.com

  + Everyone has their own god. +