move-bydate.ps1

function Move-ByDate {
    param(
        $Path = '.',
        $Destination
    )

    Get-ChildItem -Path $Path | ForEach-Object {
        $Date = $_.LastWriteTimeUtc | Get-Date -f yyyy.M

        $DestPath = Join-Path $Destination $Date

        if (-not (Test-Path $DestPath)) {
            New-Item -Path $DestPath -ItemType Directory
        }

        Move-Item -Path $_.FullName -Destination $DestPath
    }
}