As @Ravi pointed out in his answer, MySQL accepts dates in the format YYYY-MM-DD. Quoted from 11.1.5. Date and Time Types1:
Although MySQL tries to interpret values in several formats, date
parts must always be given in year-month-day order
For this, you can use str_todate()2 function to format it:
str_to_date('12/25/2012', '%m/%d/%Y);
This way, these input strings will be stored in your database as date objects(without any specific date format). Later, if you want to output these dates in a specific format you can use DATE_FORMAT3 to format it. Something like:
SELECT DATE_FORMAT(datefield, '%Y-%m-%d') FROM Test;
--2012-12-25
1, 2, 3: Links and refs, that you asked for.