tidy download directory on windows

tidy.ps1

# tidy up the ~/Downloads directory

cd C:\Users\me\Downloads
$week_ago = (Get-Date).AddDays(-7)
dir | Select-Object {
    $last_access = $_.lastAccessTime
    if ($last_access -lt $week_ago) {
        $path = "{0:yyyyMM}" -f $last_access
        if (! (Test-Path $path)) { mkdir $path } 
        if ($_.FullName -notmatch "^20\d\d\d\d") { mv $_.FullName $path }
    }
}