Currently the download_dump.py script just can download the file from latest revision (f.ex https://dumps.wikimedia.org/idwiki/latest/ )[1]. We can add support to this script to download from "date specified" revision f.ex https://dumps.wikimedia.org/idwiki/20171001/.
For the implementation, we can perhaps add a new parameter -revision to the script, and then if the user don't specify the -revision we will assume that the revision is latest.