ALH

2.3.0

Public/ConvertTo-ALHDateTime.ps1

<#PSScriptInfo
 
.VERSION 1.2.0
 
.GUID 044cd38b-8558-4820-b412-c56121c12018
 
.AUTHOR Dieter Koch
 
.COMPANYNAME
 
.COPYRIGHT (c) 2021-2023 Dieter Koch
 
.TAGS
 
.LICENSEURI https://github.com/admins-little-helper/ALH/blob/main/LICENSE
 
.PROJECTURI https://github.com/admins-little-helper/ALH
 
.ICONURI
 
.EXTERNALMODULEDEPENDENCIES
 
.REQUIREDSCRIPTS
 
.EXTERNALSCRIPTDEPENDENCIES
 
.RELEASENOTES
    1.0.0
    Initial release
 
    1.1.0
    Added parameter 'AsLocalTime'
 
    1.2.0
    Added pipeline support. Set defaut value to current date/time for parameter 'DateTime'
 
#>


<#
 
.DESCRIPTION
 Contains a function to convert miliseconds since 1970 or 1601 or ticks since 1601 to a DateTime value.
 
#>


function ConvertTo-ALHDateTime {

    <#
    .SYNOPSIS
    Converts miliseconds since 1970 or 1601 or ticks since 1601 to a DateTime value.
 
    .DESCRIPTION
    Converts miliseconds since 1970 or 1601 or ticks since 1601 to a DateTime value (by defaults in UTC time).
    The function returns $null
 
    .PARAMETER DateTimeValue
    Miliseconds since 01.01.1700 00:00:00 or miliseconds since 01.01.1601 00:00:00 or ADDateTime value.
 
    .PARAMETER AsLocalTime
    If specified, the resulting DateTime value will be interpreted in local time zone, instead of UTC.
 
    .EXAMPLE
    ConvertTo-ALHDateTime -DateTimeValue 13270022798437
 
    DateTimeBase1970 DateTimeBase1601 DateTimeBaseAD
    ---------------- ---------------- --------------
    06.07.2390 03:26:38 06.07.2021 03:26:38 16.01.1601 08:36:42
 
    Convert a int64 value representing an miliseconds since 01.01.1601 to date/time in UTC format.
 
    .EXAMPLE
    ConvertTo-ALHDateTime -DateTimeValue 13270022798437
 
    DateTimeBase1970 DateTimeBase1601 DateTimeBaseAD
    ---------------- ---------------- --------------
    06.07.2390 03:26:38 06.07.2021 03:26:38 16.01.1601 08:36:42
 
    Convert a int64 value representing an miliseconds since 01.01.1601 to date/time in UTC format.
 
 
    .EXAMPLE
    (Get-ADUser -Filter * -Property lastLogonTimeStamp).lastLogonTimeStamp | ConvertTo-ALHDateTime
 
    DateTimeBase1970 DateTimeBase1601 DateTimeBaseAD
    ---------------- ---------------- --------------
                                      04.11.2022 09:43:10
                                      04.11.2022 09:43:10
                                      23.02.2020 17:59:40
                                      23.02.2020 17:59:40
                                      23.11.2015 05:57:05
                                      09.11.2022 11:14:48
 
    This example shows how to retrieve the lastLogonTimeStamp for all users in Active Directory and get the DateTime value
    of for it.
 
    .INPUTS
    System.Int64
 
    .OUTPUTS
    PSCustomObject
 
    .NOTES
    Author: Dieter Koch
    Email: diko@admins-little-helper.de
 
    .LINK
    https://github.com/admins-little-helper/ALH/blob/main/Help/ConvertTo-ALHDateTime.txt
    #>

    [CmdletBinding()]
    param
    (
        [Parameter(Mandatory, ValueFromPipeline, ValueFromPipelineByPropertyName)]
        [double[]][AllowNull()]
        $DateTimeValue,

        [switch]
        $AsLocalTime
    )

    begin {
        $DT1970 = Get-Date -Date "1970-01-01T00:00:00"
        $DT1601 = Get-Date -Date "1601-01-01T00:00:00"

        $DateTimeConverted = [PSCustomObject]@{
            DateTimeBase1970 = $DT1970.AddMilliseconds($DateTimeValueElement)
            DateTimeBase1601 = $DT1601.AddMilliseconds($DateTimeValueElement)
            DateTimeBaseAD   = [DateTime]::FromFileTime($DateTimeValueElement)
        }
    }

    process {
        if ($null -eq $DateTimeValue) {
            # return a PSCustomObject with $null values for each property
            $DateTimeConverted
        }
        else {
            foreach ($DateTimeValueElement in $DateTimeValue) {
                try {
                    if (($DateTimeValueElement * 10000) -lt [DateTime]::MaxValue.Ticks) {
                        [datetime]$LocalDTBase1970 = $DT1970.AddMilliseconds($DateTimeValueElement)
                        [datetime]$LocalDTBase1601 = $DT1601.AddMilliseconds($DateTimeValueElement)
                    }
                }
                catch {
                    $_
                }

                try {
                    [datetime]$LocalDTBaseAD = [DateTime]::FromFileTime($DateTimeValueElement)
                }
                catch {
                    $_
                }

                if ($AsLocalTime.IsPresent) {
                    $DateTimeConverted.DateTimeBase1970 = $( if ($null -ne $LocalDTBase1970) { $LocalDTBase1970 } )
                    $DateTimeConverted.DateTimeBase1601 = $( if ($null -ne $LocalDTBase1601) { $LocalDTBase1601 } )
                    $DateTimeConverted.DateTimeBaseAD = $( if ($null -ne $LocalDTBaseAD) { $LocalDTBaseAD } )
                }
                else {
                    $DateTimeConverted.DateTimeBase1970 = $( if ($null -ne $LocalDTBase1970) { $LocalDTBase1970.ToUniversalTime() } )
                    $DateTimeConverted.DateTimeBase1601 = $( if ($null -ne $LocalDTBase1601) { $LocalDTBase1601.ToUniversalTime() } )
                    $DateTimeConverted.DateTimeBaseAD = $( if ($null -ne $LocalDTBaseAD) { $LocalDTBaseAD.ToUniversalTime() } )
                }

                $DateTimeConverted
            }
        }
    }
}


#region EndOfScript
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