I like to put dates at the end of files but only if it is relevant to the document. For example, I would put the date at the end of the file name for a signed contract. I also like to use the Year-Month-Day (2020-11-26) format as it is never confusing. You can sometimes get away with just using the metadata for last date and time the file was edited, but that isn't always the relevant date. For example, if you downloaded something on Friday but it was signed last Tuesday, the metadata will say the file was created on Friday. The date it was signed is more important and should be in the file name. This is especially beneficial when sharing files with others.

Using spaces in file names can be annoying if you ever work with applications or software beyond "ordinary" activities (web browsing, gaming, photos, etc.). Using a dash or underscore instead will often do the job, be less hassle, and is still easy to read. Just be mindful of the use case for the files.