Hi,
There are a number of additional possibilities I have uncovered that could help you with but if you can provide a bit more of a background it would help.
One of the easiest methods would be to ensure you have a username always set, and you can then at the end of the day list all tiddlers created by or modified by that user id.
If you want to capture the installation of external tiddlers and plugins as well, which would not carry your user ID, install the bundles plugin and activate the import bundle which records all the imports in a single bundle. The bundles plugin also allows you to set up a filter bundle which will be the way to identify all your tiddlers (you can use multiple filters) to export and delete them when you are finished.
Using the naming standards available also simplifies it, like I use $:/PSaT/ as a prefix to all the system tiddlers I create.
Regards
Tony