Based on the Import Activity file specification input box, you may think that only three wildcards are available — year, month and day:
However, in the Salesforce Marketing Cloud/ExactTarget Help page for Import Activities, you’ll notice that there are more listed:
So if you need some more granularity in files you’re uploading to your ET FTP share, yes, you can use minutes and seconds.
Don’t forget about the case-sensitivity disclaimer. Because ET utilizes non-Microsoft CDNs for FTP and image hosting, your file name specifications must match exactly.
For further reading: