I’m not sure what you mean by ‘knowledge of these dates put in a file name’? The following may be of no use, but as you requested info as to handling files/documents by date, I’ll share below.
As you note in your original post, Devonthink is more than capable of recognising (i.e. ‘having knowledge’) dates in a file name. I work with historical documents, where the date (when a letter/memo was written, pamphlet published, etc) is a crucial element of the document’s information. Like Korm, I save the majority of my files on DTPO with the date prefixed (though I use YYYY-MM-DD, as I find that easier to read).
I have multiple folders within a database for different archival repositories (for which you might read read multiple folders for different clients), each roughly spanning the same time frame. I use Smart Groups to isolate files by date when necessary. In the attached screenshot, you can see how I isolate files relevant to the year 1787, and on another instance all files dated for the years between 1700 and 1710. Thus for example if I’m looking for a letter I know was published in that decade, but can’t remember who wrote it or in what folder of my DB it might be residing, I can scan through the Smart Group’s contents until I locate it. It’s also occasionally very useful for me to see what was published/written in a single year or range of years. Greater granularity could be added by making the parameter Name -> Matches -> 1787-05, and so on.
My file names will also include, where practical, the names of important people associated with each file, which can help when scanning lists for individuals (who might often appear in files scattered across several folders). However, I find Search better for this operation because I tend to be as brief as possible with filenames, especially since DT doesn’t allow you to ‘wrap’ filenames so that they are not obscured.
As for information contained within files that is not date specific (such as a location), or names not associated with the creation of the file (which in my case is usually the author or recipient), search is the best bet, assuming that you are working with files in which the text is recognisable.
I haven’t really used the See Also and Classify function, which might be what you’re looking for when you mention Similarity and Autofiling. I prefer not to let AI file my material for me. When adding files to my DBs (if they are not created internally), I name and then save them to a folder on my desktop which has the folder action Import to Selected Group and Delete attached. I have a shortcut to this folder in my Finder sidebar rather than the default Global Inbox.
Most of my files are named and filed manually in this way, because my needs constantly change and I quickly found that any attempt to automate the process required too much tinkering to remain up to date. As a result I’m forced to think more deeply about my files, and so tend to have a better recollection of both their content and their location. This suits me fine!
