Powershell | 有没有办法过滤掉数组中小于 6 个月大的项目？

Question

Background Info

I've written a script that uses an API to get me all users of an application, which I've written to specifically get their email addresses and the last time they logged in. The script stores the results in an array, and then writes that array to a CSV file. I then also have written a separate script using another API endpoint, that deactivates users within this application based on the email addresses I pass to it from a CSV.

Currently, I'm deactivating users who haven't signed in for 6 months or more and using Google Sheets/Excel to manipulate the initial data output, to filter results to only those users who last date logged in is 6 months ago or greater, exporting that as a separate CSV to then import into the deactivation script.

Here's the question!

Is there a way within powershell that I can complete the data manipulation completely, so I may be able to link these scripts into one, or be able to complete these actions without having to manually manipulate the data outside of powershell?

To make things slightly more challenging (to me, as a moderately experienced powershell user, but nowhere near an expert:) is that the date format output from the API call is in this format: 2020-01-01T15:00:00Z

Answer 1

I have under 50 reputation points, so I can't comment directly, but a solution would be to cast the date output string to the datetime type. The string looks to be under the Zulu date format, which is essentially UTC (doesn't observe daylight saving time).

[datetime]'2020-01-01T15:00:00Z'
# Results in Wednesday, January 1, 2020 10:00:00 AM.

([datetime]'2020-01-01T15:00:00Z').AddDays(-1)
# Results in Tuesday, December 31, 2019 10:00:00 AM.

What @vonPryz mentioned is that once done, you can play around with the AddDays method and add the days elapsed in the form of negative integers.

Answer 2

Thanks @Dan and @vonPryz for the support - have used both of these in my result!

For context, in the script that queries the API for all users data, it stores the result of their last login time in a value with header of "Last Login" - in retrospect, I would have used LastLogin as that means I don't need quotes when calling later on. I also have a function that imports the CSV file after selecting the file using an FileDialog box and assigned it to $users

I also did a bit more reading on other methods that can be used with Get-Date, and found there's also an addmonths() method, so used addmonths(-6)

Here's the link to the post I found on this.

Here's the code that I used to get my final result

$currentDate = get-date
$filterDate = $currentDate.addmonths(-6)
$newTable = @()

Foreach($user in $users){
    $lastLogin = $user.'last login'
    if ($lastLogin -eq "") {
  
    } else {
       $convertedLastLogin = [datetime]$lastlogin
    }

    if ($convertedLastLogin -lt $filterDate -or $lastlogin -lt $filterDate) {
        $newTable += $user
    }
}

I can then export the $newTable output to a CSV if I want to. I compared this to the data I was getting if I manually manipulated, and it matched perfectly too, so pretty sure I got there in the end!