For the birthday of our kids my wife creates hard-copy Photo Books. The procedure is time consuming but worth every minute.

Recently I migrated to the new Photos app on my MacBook. The Software for creating the book is on Windows. This means exporting the pictures to disk and moving them to another device (am looking into Parallels) Since the export creates a folder per “event” combining them into monthly folders would take ages. The event folders came with the month spelled out and that is what I used to get the files into the month folder.

See the script below.
First get-childitem selects all folders in the current folder.
Then select all folders that have october in the name.
Get the childitems (the pictures inside the folders).
Last move the pictures to a new folder called 10-2015.

get-childitem | where name -Like '*october*' | `
    Get-ChildItem -Recurse | `
    Move-Item -Destination f:\10-2015

Powershell actually did it in 5 minutes. 30 seconds to figure out the syntax and 4 minutes waiting for the copy of the files to be moved.