How does the database purge work with date frames?

Records are purged according to the date frame provided. 

For example, if someone visited everyday from 01/01/2015-06/01/2015 and you purge everything older than 05/01/2015, the person will not be deleted but their visits from 01/01/2015 till 04/01/2015 will be deleted. If you purged records older than 6/2/2015, the person as well as their visit data, including pictures, will be deleted.