I have created this little quick and dirty script.
Things have been put in more variables than strictly needed, they could be combined in a single line, but I feel this adds clarity which I hope help you understand what happens.
As a note, I have used the date the item was last written to (created or edited).
If you want only the date the file was created and not the time the file was last edited, you could change LastWriteTime to CreationTime
#Load all files from the folder you wish to move on
$items = Get-ChildItem -Path "C:\SomeFolder\RestofPathToYourFiles"
foreach($item in $items) {
#Creates variables for year, month and day
$FolderYear = "$($item.LastWriteTime.Year)"
$FolderMonth = "$($item.LastWriteTime.Month)"
$FolderDay = "$($item.LastWriteTime.Day)"
#create variable with the new directory path
$NewPath = $item.Directory.FullName + "\" + $FolderYear + "\" + $FolderMonth + "\" + $FolderDay
#create variable with the new full path of the file
$NewFullPath = $NewPath + "\" + $item.Name
#test if the folder already is created, if not, create it
if((Test-Path -Path $NewPath) -eq $false) {
New-Item -Force -path $NewPath -Type Directory
}
#move the item to the new folder
Move-Item -Path $item.FullName -Destination $NewFullPath -Force
}