select personid from table1 t1
left join table2 t2
on t1.personid = t2.personid and t2.personid is null
where date between '21020801' and '20120805' and t1.personid like '95*'

select personid from table1 t1
left join table2 t2
on t1.personid = t2.personid 
where date between '21020801' and '20120805' and t1.personid like '95*' and t2.personid is null

The First will show data from Table1 with respect to the referencing data from Table1 to Table2.
Second will Show data from Table1 BUT excluding the the JOIN data.

Here's a good example:
http://www.codeproject.com/Articles/33052/Visual-Representation-of-SQL-Joins