datetime comparison letting thread proceed when shouldn't - powershell

Question

I have a backup script that puts files in a dated directory every night. I have another script, below, that goes through a list of dated directories and if it's within the range I want to delete, I will delete the directory, keeping the Saturday dated file. For some reason, for the dir dated Saturday, 1/12/2019, it's being deleted, even though the if statement should indicate it wouldn't be deleted.
This is my code:
function WeeklyCleanup($folderWeeklyCleanupDatedSubdirs) {
#find out date range to cleanup
$lastSaturday = GetLastSaturdayDate
$lastSaturday = [datetime]$lastSaturday
$weekAgoSunday = GetWeekAgoSundayDate
$weekAgoSunday = [datetime]$weekAgoSunday
#find out filename with Saturday date before current date but within week
Get-ChildItem $folderWeeklyCleanupDatedSubdirs | ForEach-Object {
write-output $_
#check to see if item is before day we want to remove
$temp = $_
$regex = [regex]::Matches($temp,'([0-9]+)-([0-9]+)-([0-9]+)')
if($regex.length -gt 0) #it matched
{
$year = $regex[0].Groups[1].Value
$month = $regex[0].Groups[2].Value
$day = $regex[0].Groups[3].Value
write-output $year
write-output $month
write-output $day
write-output "*************"
$dirDate = $regex[0].Groups[0].Value + " 12:00:00 PM"
write-output $dirDate
if($dirDate.length -gt 0) #it matched
{
$dateTimeObjectFromRegex = [datetime]$dirDate
##########this next statement is letting $dateTimeObjectFromRegex of 1/12/2019 through when it shouldn't. See time comparison below
if(([datetime]$dateTimeObjectFromRegex -lt [datetime]$lastSaturday) -and ([datetime]$dateTimeObjectFromRegex -ge [datetime]$weekAgoSunday)) #we're removing extra ones over last week, keep Saturday
{
$dirPathToRemove = Join-Path -path $folderWeeklyCleanupDatedSubdirs -ChildPath $temp.ToString()
Get-ChildItem -Path $dirPathToRemove #list the dir
#remove dir
if(-Not (Test-Path $dirPathToRemove )) #-PathType Container
{
$global:ErrorStrings.Add("Exception: No such path, $dirPathToRemove;; ")
write-output "++ Error: An error occured during copy operation. No such path, $dirPathToList ++"
}
else
{
#remove dir and subdirs
Remove-Item $dirPathToRemove -Force -Recurse
Get-ChildItem -Path $dirPathToRemove #list the dir
}
#Write-Output $_
#Write-Output " 1 "
} #if within last week
} #if dirDate length
} #if regex matched
} #get-childItem
}
function GetLastSaturdayDate()
{
$date = Get-Date #"$((Get-Date).ToString('yyyy-MM-dd'))"
#for($i=1; $i -le 7; $i++){
# if($date.AddDays(-$i).DayOfWeek -eq 'Saturday') #if found Saturday
# {
# $date.AddDays(-$i)
# $newDate = $date.AddDays(-$i)
# break
# }
#}
$newdate = $date.AddDays(-($date.DayOfWeek+1)%7)
return $newdate
}
function GetWeekAgoSundayDate()
{
$numberOfWeeks = 1; #week ago
$date = Get-Date #"$((Get-Date).ToString('yyyy-MM-dd'))"
#for($i=1; $i -le 7; $i++){
# if(($date.AddDays(-$i).DayOfWeek -eq 'Sunday') -and ($date.AddDays(-$i) -ne $date)) #if found a Sunday and it's not today
# {
# $date.AddDays(-$i)
# $newDate = $date.AddDays(-$i)
# break
# }
#}
#$newdate = $date.AddDays(-($date.DayOfWeek+1)%0)
$numDaysSincePreviousDate = $date.DayOfWeek.value__ + 0 #0 is Sunday
([System.DateTime] $previousDayOfWeek = $date.AddDays(- $numDaysSincePreviousDate)) | Out-Null
$previousDate = $previousDayOfWeek.AddDays(-($numberOfWeeks *7)).ToString("MM-dd-yyyy")
return $previousDate
}
The WeeklyCleanup script is called with this parameter:
$folderToCleanupDatedSubdirs = [System.IO.DirectoryInfo]"E:\Bak_TestDatedFolderCleanup"
For time comparison:
Directory item toLocRobo_2019-01-12 - Once I get regex with timestamp, I add the time in of 12:00:00 PM for the $dirDate variable. This becomes $dateTimeObjectFromRegex. Debugger shows it as Saturday, January 12, 2019 12:00:00 PM
When I run the program, I get $lastSaturday as Saturday, January 12, 2019 3:59:04 PM
When I run the program, debugger also shows $weekAgoSunday as Sunday, January 6, 2019 12:00:00 AM
From what I can see, it shouldn't be getting through that if statement to delete the dir for 1/12/2019.
I tried casting the dates to datetime to make sure it wasn't doing a string comparison in the if statement, even though I casted it above.
I've been looking at these links for more info on this, but it looks correct to me:
dateTimeComparisons not working expectedly
convert string to datetime
All I can think is that it's still treating the datetime in the first part of the if statement comparison like a string, so it's thinking 3:59 PM is greater than 12:00 PM. Any ideas how to get this date check to work? I don't care about times, just want to make sure it doesn't get rid of the Saturday-dated file from this past week, but only cleanup other dir's over that week.
Update
Made changes suggested by #brianist below, and it worked great. This is what it looks like so far. Saturday and Sunday functions haven't changed. He's asking me to post it. If he has any other suggestions how to get it to treat/compare what's returned from the last Saturday and weekAgoSunday functions as dates, without the cast, that'd make it look less clunky/easier to read. Thanks Brian!
#do weekly cleanup of DisasterBackup folder
function WeeklyCleanup($folderWeeklyCleanupDatedSubdirs) {
#find out current date
$currentDate = "$((Get-Date).ToString('yyyy-MM-dd'))" #example 2019-01-15
$currentDayOfWeek = (get-date).DayOfWeek.value__ #returns int value for day of week
#find out current day of week
$lastSaturday = GetLastSaturdayDate
$lastSaturday = [datetime]$lastSaturday #if we take away extra casts it won't do comparison line (-lt and -ge)
$weekAgoSunday = GetWeekAgoSundayDate
$weekAgoSunday = [datetime]$weekAgoSunday #if we take away extra casts it won't do comparison line (-lt and -ge), and can't move cast before function call because it isn't recognizing function anymore if I do
#find out filename with Saturday date before current date but within week
#get each dir item to check if we need to remove it
Get-ChildItem $folderWeeklyCleanupDatedSubdirs | ForEach-Object {
write-output $_
#check to see if item is before day we want to remove
$temp = $_
if($_.Name -match '(\d{4}-\d{2}-\d{2})$'){ #regex
write-output $Matches[1]
$dirDate = Get-Date $Matches[1] #turn regex into date
if(([datetime]$dirDate.Date -lt [datetime]$lastSaturday.Date) -and ([datetime]$dirDate.Date -ge [datetime]$weekAgoSunday.Date)) #we're removing extra ones over last week, keep Saturday
{
$dirPathToRemove = Join-Path -path $folderWeeklyCleanupDatedSubdirs -ChildPath $temp.ToString()
Get-ChildItem -Path $dirPathToRemove #list the dir
#remove dir
if(-Not (Test-Path $dirPathToRemove )) #-PathType Container
{
$global:ErrorStrings.Add("Exception: No such path, $dirPathToRemove;; ")
write-output "++ Error: An error occured during copy operation. No such path, $dirPathToList ++"
}
else
{
#remove dir and subdirs
Remove-Item $dirPathToRemove -Force -Recurse
Get-ChildItem -Path $dirPathToRemove #list the dir
}
} #if within last week
} #if regex matched
} #get-childItem
}

Answer 1

Re-reading your last sentence, I now see that your intention is to ignore times, not to include them in your comparison.
You are right to want to use [DateTime] objects when comparing, but do note that those objects always include a time.
Conveniently you can use the .Date property of such an object which returns a new one, with the time set to midnight. This is useful for comparing because the time would no longer be a factor.
Pulling out my modified if statement from below, you can do it like this:
if ($dirDate.Date -lt $lastSaturday.Date -and $dirDate.Date -ge $weekAgoSunday.Date) {
# do stuff
}
Now you're only comparing dates, and ignoring time!
Based on what you're showing it looks like the if statement is working as expected. To summarize, you say that:
$dateTimeObjectFromRegex is Saturday, January 12, 2019 12:00:00 PM
$lastSaturday is Saturday, January 12, 2019 3:59:04 PM
$weekAgoSunday is Sunday, January 6, 2019 12:00:00 AM
The conditional is:
if(([datetime]$dateTimeObjectFromRegex -lt [datetime]$lastSaturday)
-and ([datetime]$dateTimeObjectFromRegex -ge [datetime]$weekAgoSunday))
Therefore in pseudo-code it's:
if (
("January 12, 2019 12:00:00 PM" is earlier than "January 12, 2019 3:59:04 PM") # true
and
("January 12, 2019 12:00:00 PM" is later or the same as "January 6, 2019 12:00:00 AM") # true
) # true
I do want to point out that you are doing an awful lot of unnecessary datetime chopping and casting, and cleaning that up would help with readability and with debugging these types of issues.
$lastSaturday = GetLastSaturdayDate
$lastSaturday = [datetime]$lastSaturday
$weekAgoSunday = GetWeekAgoSundayDate
$weekAgoSunday = [datetime]$weekAgoSunday
Your functions already return [DateTime] objects, so there's no need for those casts.
$temp = $_
$regex = [regex]::Matches($temp,'([0-9]+)-([0-9]+)-([0-9]+)')
if($regex.length -gt 0) #it matched
{
$year = $regex[0].Groups[1].Value
$month = $regex[0].Groups[2].Value
$day = $regex[0].Groups[3].Value
write-output $year
write-output $month
write-output $day
write-output "*************"
$dirDate = $regex[0].Groups[0].Value + " 12:00:00 PM"
write-output $dirDate
This is quite complex, you could simplify it down to something like this:
if ($_.Name -match '(\d{4}-\d{2}-\d{2})$') {
# in here, you know the match was successful
$dirDate = Get-Date $Matches[1] # double check this, might need .Groups or something
if ($dirDate -lt $lastSaturday -and $dirDate -ge $weekAgoSunday) {
# do stuff
}
}
Probably some more optimizations etc. Hope this was helpful!