I too add dates to file names even though I know the creation date is part of the file's meta-data. When files are moved between systems the meta-data is not always preserved. This chance of loss is also what thwart me from using a tagging tool as I can not be assured that the tags will be preserved between systems. And so, the trifecta of low-ceremony document management are
- a good title,
- a date in the title, and
- a good full-text search.