OLDSNAP=20230115
SNAPDATE=20230505
mkdir /mirror/stable/$SNAPDATE
cp -rl /mirror/upstream/osg /mirror/stable/$SNAPDATE/osg
cp -rl /mirror/upstream/epel /mirror/stable/$SNAPDATE/epel

copy any other directories from most recent snapshot into new snapshot

also make a snapshot for internal (password protected) packages
cp -rl /mirror/stable/internal/$OLDSNAP /mirror/stable/internal/$SNAPDATE
update packages as desired