Powershell脚本正在根据上次写入时间移动错误的文件

Question

我有一个Powershell脚本，它使用文件的上次写入时间将文件从一个文件夹移动到另一个文件夹。脚本正在检查上次写入时间是否小于或等于指定日期。似乎随着年份的变化，这不再正常工作。我的文件修改日期为 12/29/2016、12/30/2016 和 1/2/2017。12/29 文件应该是唯一移动的文件，因为今天是 1 年 3 月 2017 日，并且脚本使用该日期减去 5 天。因此，它应该只移动小于或等于 12/29/2016 的任何内容。但是，1/2/2017 文件也被移动了。脚本如下，关于为什么会发生这种情况的任何想法。

#Grab the day of the week it is TODAY
$DayofWeek = (Get-Date).DayofWeek
#Set the location we are going to be Pulling Files From
$FromPath = "path i'm copying files from goes here"
#Set the Location we are going to copy file To
$ToPath = "path i'm copying files to"
#Set a Default Value for DaysBack to Zero
$DaysBack = 0
#Set the Days Back if it is Tuesday through Friday
switch ($DayofWeek)
{
    "Tuesday"   { $DaysBack = -5 }
    "Wednesday" { $DaysBack = -5 }
    "Thursday"  { $DaysBack = -3 }
    "Friday"    { $DaysBack = -3 }
    "Saturday"  { $DaysBack = -3 }
    #If today is not an above day then tell the user today no files should be moved
    default     { Write-host "No files to move!" }
}
#if DaysBack does not equal ZERO then there are files that need to be moved!
if($DaysBack -ne 0) {
    Get-ChildItem -Path $FromPath |
    Where-Object { $_.LastWriteTime.ToString("MMddyyyy") -le (Get-Date).AddDays($DaysBack).ToString("MMddyyyy") } |
    Move-Item -Destination $ToPath
}

Answer 1

$date1 = Get-Date -Year 2017 -Month 1 -Day 2
$date2 = Get-Date -Year 2016 -Month 12 -Day 29
$date1 -gt $date2
#returns True
$date1.ToString("MMddyyyy") -gt $date2.ToString("MMddyyyy")
# "01022017" -gt "12292016"
# returns False

您可以使用

if($DaysBack -ne 0) {
    Get-ChildItem -Path $FromPath |
    Where-Object { $_.LastWriteTime -le (Get-Date).AddDays($DaysBack) } |
    Move-Item -Destination $ToPath
}

或

if($DaysBack -ne 0) {
    Get-ChildItem -Path $FromPath |
    Where-Object { $_.LastWriteTime.ToString("yyyyMMdd") -le (Get-Date).AddDays($DaysBack).ToString("yyyyMMdd") } |
    Move-Item -Destination $ToPath
}