Benetl (a free ETL tool) has been designed to work with .csv or .txt or .xls datasource files.
In order to retrieve data, you have to define an entity (something you would like to show, to calculate), a date (it is a timesamp, a moment an event appears).
Benetl is creating everything you can use, in a postgreSQL or MySQL database.
Benetl is also proposing an automatic way to retrieve data, using scheduled tasks of your system.
With Benetl, you can easily retrieve information from flat data files, filtering them and organizating them, according to date (timestamp) and entity.