We've got many questions from users regarding details of app usage. So let me give an example to clarify.
Le't say, John and Steve both attended a conference in hotel Hilton located in Downtown Los Angeles from June 5 till June 12, 2012. They met at the conference and had a very good exchange of ideas, but they did not get contact info of each other due to their very busy schedule. Later John wanted to meet Steve again to discuss his brilliant ideas, but the conference did not keep full list of all attendees. So, how can John reconnect with Steve?
Steve used the app "Past Meet" to register his attendance at the conference: he created visit record with location of Hilton Los Angeles Downtown hotel AND date range of the conference: from June 5 to June 12, 2012.
Later, John decided to use "Past Meet" to find Steve. He registers in the app and searches people who attended area with location of Hilton Los Angeles Downtown hotel as a center in 2 km radius (to cover hotel area and around it) AND in date period between June 5 and June 12, 2012. All users, who attended that area in date range, OVERLAPPING with the period between June 5 and June 12, will be found.
If John finds Steve among the users, he can send a request for connection to Steve providing details in the request message. If Steve approves his request, they can talk over in-app messenger.
So, for users to find each other, the following conditions must be met:
1) Searching user must specify area (center and specific radius) AND date range in the search request.
2) Users, who created visit records with locations within that area and with date range OVERLAPPING that date range, will be found.
3) Searching user does not necessary need to create visit record, but the person he is looking must have such record to be found.