I feel this would be resolved by using join but can't seem to figure out how

my table looks like

user - date
1 - 1-march-08
1 - 5-march-08
1 - 15-march-08
2 - 16-march-08
3 - 15-march-08
3 - 18-march-08
4 - 11-march-08
4 - 21-march-08
5 - 15-march-08

i need to find out all those users who have date more than 14-march but NOT before that

the result set would look like:-

user - date
2 - 16-march-08
3 - 15-march-08
3 - 18-march-08
5 - 15-march-08