Writing Foldernames in a Array Powershell - powershell

Question

I would like to write the directory names of several folders in an array. However, only all directory names with a date <today should be read. The directory names contain a date in this form * YYYYMMDD *
So I would have to do the following:
Borrow the date
Write the date in the form of YYYYMMDD in a variable
Read out directory names and check against the variable
Write data to an array ... do something ...
Can someone tell me how I can solve this with Powershell please?
Thank you

Answer 1

Start by retrieving all the candidate directories, then use Where-Object to extract the date part and test that it describes a date prior to today:
# Define threshold
$Today = (Get-Date).Date
# Go through all candidate directories
$oldDirectories = Get-ChildItem .\path\to\root\folder -Directory |Where-Object {
$dt = 0
# Test if directory name contains 8 consecutive digits describing a valid date
if($_.Name -match '(\d{8})' -and [datetime]::TryParseExact($Matches[1], 'yyyyMMdd', , $null, 'None', [ref]$dt)){
# We only want the ones with a date prior to today
$dt.Date -lt $today
}
else{
# Not containing a properly formatted date, we're not interested
$false
}
}
# Now we can extract the names
$oldDirectoryNames = #($oldDirectories.Name) # or #($oldDirectories |Select -Expand Name)

Answer 2

Do these directorynames start with the date?
yes
What do you mean by Borrow the date? Is that the date of today or what?
Determine the Date, Yes of today.
I read out the date accordingly and wrote it in a variable:
$Timestamp = ([datetime]::now).tostring("yyyyMMdd")
Now I want to read out all directory names which have got a Date < 1 Day and would like to process it in a foreach for further processing
Understandable?