Should date formats be specified in SQL statements? I see code from developers using implicit date conversion.  I would like a definitive answer to why they should not do this.

SELECT * from dba_objects WHERE Created &gt;= '06-MAR-2012';
Because '2012/12/1' in the US is 11 months after the same string date in Europe.

Allowing implicit conversions means you are at the mercy of location settings.

If you can name a business where 11 months is an acceptable margin of error I'll be impressed.