Functions/ConvertTo-DateTime.ps1
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function ConvertTo-DateTime { <# .SYNOPSIS Converts a formatted date string back into a datetime datatype. .DESCRIPTION Converts a formatted date string back into a datetime datatype. .PARAMETER DateString The date string that you wish to convert back to a datetime. Alias 'Date'. Can be input from the pipeline. .PARAMETER DMTF A switch parameter to display in DMTF format. Default parameter set. DmtfDateTime is of the form 'yyyyMMddHHmmss.ffffff+UUU' Where yyyy is the 4 digit year MM is the 2 digit month dd is the 2 digit day of the month HH is the 2 digit in 24 hour format (00-23, 1 pm = 13) mm is the 2 digit minute (00-59) ss is the 2 digit second (00-59) ffffff is the 6 digit microsecond + is a plus or minus to indicate offset from UTC UUU is the 3 digit number of minutes offset from UTC (000-720) .PARAMETER Unix A switch parameter to convert from a UnixEpoch which is the number of seconds since '1/1/1970 12:00:00 AM UTC'. .PARAMETER FileTime Converts a large integer filetime [int64] into a datetime string. There is a special value that returns a value of 'Never'. Filetimes are expressed in Ticks. Ticks can range from 0 - 2650467743999999999. Translating these into dates you get 0 = Monday, January 01, 1601 12:00:00.00000 AM 2650467743999999999 = Friday, December 31, 9999 11:59:59.99999 PM .PARAMETER ICSDateTime IcsDateTime is of the form 'yyyyMMddTHHmmssZ' Where yyyy is the 4 digit year MM is the 2 digit month dd is the 2 digit day of the month HH is the 2 digit in 24 hour format (00-23, 1 pm = 13) mm is the 2 digit minute (00-59) ss is the 2 digit second (00-59) T is the letter T Z is an optional suffix indicating UTC or Zulu time If the final character is NOT a Z then the time is local time. .PARAMETER Excel Switch to indicate that the datestring is in Excel format which represents dates as the number of days since (get-date 1/1/1900) .PARAMETER Format See help for Get-Date and the -Format parameter. This will parse the datestring using the Format as a template. .PARAMETER IncludeInput Switch to enable the original datetime to appear in the output. Aliased to 'IncludeOriginal' .PARAMETER UTC Switch to force the output to be in the UTC timezone. Alias of this parameter is 'Zulu' .EXAMPLE ConvertTo-DateTime '20161124225058.082190+060' If you were in the EST timezone this would return the datetime Thursday, November 24, 2016 4:50:58 PM .EXAMPLE ConvertTo-DateTime -DateString 946684799 -Unix -UTC Would return Friday, December 31, 1999 11:59:59 PM .EXAMPLE ConvertTo-DateTime '20161124T225058Z' -ICSDateTime If in the EST timezone this would return Thursday, November 24, 2016 5:50:58 PM .EXAMPLE ConvertTo-DateTime 131619940792563529 -FileTime -UTC Would return Thursday, February 1, 2018 9:27:59 PM .EXAMPLE ConvertTo-DateTime '20-04-01' -Format 'yy-MM-dd' Would return Wednesday, April 1, 2020 12:00:00 AM .EXAMPLE ConvertTo-DateTime -DateString 946684799 -Unix -Verbose Would return VERBOSE: Starting [ConvertTo-DateTime] VERBOSE: ParameterSetName [Unix] VERBOSE: Your local timezone is '(UTC-05:00) Eastern Time (US & Canada)' VERBOSE: The date '12/31/1999 18:59:59' is 946684799 seconds in the future of '01/01/1970 00:00:00' UTC Friday, December 31, 1999 6:59:59 PM VERBOSE: Ending ConvertTo-DateTime .NOTES Info: For further information on DMTF time formats see https://docs.microsoft.com/en-us/windows/desktop/wmisdk/cim-datetime Added Excel functionality #> #region parameter [CmdletBinding(DefaultParameterSetName = 'DMTF',ConfirmImpact='None')] [OutputType('datetime')] [Diagnostics.CodeAnalysis.SuppressMessageAttribute('PSReviewUnusedParameter','')] Param ( [Parameter(Mandatory, ValueFromPipeline, Position = 0, ParameterSetName = 'DMTF')] [Parameter(Mandatory, ValueFromPipeline, Position = 0, ParameterSetName = 'Unix')] [Parameter(Mandatory, ValueFromPipeline, Position = 0, ParameterSetName = 'FileTime')] [Parameter(Mandatory, ValueFromPipeline, Position = 0, ParameterSetName = 'ICSDateTime')] [Parameter(Mandatory, ValueFromPipeline, Position = 0, ParameterSetName = 'Format')] [Parameter(Mandatory, ValueFromPipeline, Position = 0, ParameterSetName = 'Excel')] [Alias('Date')] [string[]] $DateString, [Parameter(ParameterSetName = 'DMTF')] [switch] $DMTF, [Parameter(ParameterSetName = 'Unix')] [switch] $Unix, [Parameter(ParameterSetName = 'FileTime')] [switch] $FileTime, [Parameter(ParameterSetName = 'ICSDateTime')] [switch] $ICSDateTime, [Parameter(ParameterSetName = 'Format')] [string] $Format, [Parameter(ParameterSetName = 'Excel')] [switch] $Excel, [Parameter(ParameterSetName = 'DMTF')] [Parameter(ParameterSetName = 'Unix')] [Parameter(ParameterSetName = 'FileTime')] [Parameter(ParameterSetName = 'ICSDateTime')] [Parameter(ParameterSetName = 'Format')] [Parameter(ParameterSetName = 'Excel')] [Alias('IncludeOriginal')] [switch] $IncludeInput, [Parameter(ParameterSetName = 'DMTF')] [Parameter(ParameterSetName = 'Unix')] [Parameter(ParameterSetName = 'FileTime')] [Parameter(ParameterSetName = 'ICSDateTime')] [Parameter(ParameterSetName = 'Format')] [Parameter(ParameterSetName = 'Excel')] [Alias('Zulu')] [switch] $UTC ) #endregion parameter begin { Write-Verbose -Message "Starting [$($MyInvocation.Mycommand)]" Write-Verbose -Message "ParameterSetName [$($PsCmdlet.ParameterSetName)]" $BeginUnixEpoch = New-Object -TypeName DateTime -ArgumentList 1970, 1, 1, 0, 0, 0, ([DateTimeKind]::Utc) $DmtfRegex = '[0-9][0-9][0-9][0-9][0-9][0-9][0-9][0-9][0-9][0-9][0-9][0-9][0-9][0-9]\.[0-9][0-9][0-9][0-9][0-9][0-9][+-][0-9][0-9][0-9]' $DmtfRegex = '^(\d{14})\.(\d{6})[+-](\d{3})$' $MaxTicks = 2650467743999999999 $Never = 9223372036854775807 $ICSDateTimeregexp = '^(\d{8})(T)(\d{6})(Z)?$' $strCurrentTimeZone = (Get-CimInstance -ClassName win32_timezone -Verbose:$false).Description Write-Verbose -Message "Your local timezone is '$strCurrentTimeZone'" } process { foreach ($DS in $DateString) { Write-Verbose -Message "Current datestring is [$DS]" switch ($PsCmdlet.ParameterSetName) { 'DMTF' { Write-Verbose -Message "DTMF is [$DS]" Write-Verbose -Message "Regex is [$dmtfregex]" $prop = ([ordered] @{ DMTF = $DS } ) if ( -not ($DS -match $DmtfRegex)) { Write-Verbose -message "The DMTF date time should be of the form 'YYYYMMDDHHmmss.ffffff+###'" $ReturnVal = $null } else { $ReturnVal = ([Management.ManagementDateTimeConverter]::ToDateTime("$DS")) } if ($UTC) { $ReturnVal = ConvertTo-UTC -Date $ReturnVal -Verbose:$false } $prop.DateTime = $ReturnVal Write-Verbose -Message "ReturnVal is [$ReturnVal]" } 'Unix' { $prop = ([ordered] @{ Unix = $DS } ) $ReturnVal = ConvertFrom-UTC -Date ( $BeginUnixEpoch.AddSeconds($DS) ) -Verbose:$false if ($UTC) { $ReturnVal = ConvertTo-UTC -Date $ReturnVal -Verbose:$false } Write-Verbose -Message "The date '$ReturnVal' is $DS seconds in the future of '$BeginUnixEpoch' UTC" $prop.DateTime = $ReturnVal } 'FileTime' { $prop = ([ordered] @{ FileTime = $DS } ) if ( ([int64] $DS) -gt $MaxTicks ) { Write-Verbose -Message "The number of ticks passed $FileTime is greater than $MaxTicks" if ( ([int64] $DS) -eq $Never ) { Write-Verbose -Message "The number of ticks passed $FileTime equals the value for Never $Never" $ReturnVal = ([datetime]::MaxValue) } else { Write-Verbose -Message "The number of ticks passed $FileTime is greater than $MaxTicks but is less than Never $Never" $ReturnVal = 'Invalid' } } else { Write-Verbose -Message "The number of ticks passed $FileTime is within the valid range of 0 - $MaxTicks" $ReturnVal = [datetime]::FromFileTime($DS) if ($UTC) { $ReturnVal = ConvertTo-UTC -Date $ReturnVal -Verbose:$false } } if ($ReturnVal -ne 'Invalid' -and $UTC) { $ReturnVal = ConvertTo-UTC -Date $ReturnVal -Verbose:$false } $prop.DateTime = $ReturnVal } 'ICSDateTime' { $prop = ([ordered] @{ ICSDateTime = $DS } ) if ( -not ($DS -match $IcsDateTimeregexp)) { Write-Verbose -message "The ICS date time should be of the form 'yyyymmddTHHMMSSZ'" $ReturnVal = 'Invalid' } else { if ( $matches[4]) { # the ICS datetime ends with 'Z' $ReturnVal = [datetime]::parseexact($DS, 'yyyyMMddTHHmmssZ', $null) } else { $ReturnVal = [datetime]::parseexact($DS, 'yyyyMMddTHHmmss', $null) } } if ($ReturnVal -ne 'Invalid' -and $UTC) { $ReturnVal = ConvertTo-UTC -Date $ReturnVal -Verbose:$false } $prop.DateTime = $ReturnVal } 'Format' { $prop = ([ordered] @{ DateString = $DS; Format = $Format } ) $ReturnVal = [datetime]::parseexact($DS, $Format, $null) if ($UTC) { $ReturnVal = ConvertTo-UTC -Date $ReturnVal -Verbose:$false } $prop.DateTime = $ReturnVal } 'Excel' { $prop = ([ordered] @{ Excel = $DS } ) $ReturnVal = (get-date -Date 1/1/1900 ) + [timespan]::FromDays($DS) if ($UTC) { $ReturnVal = ConvertTo-UTC -Date $ReturnVal -Verbose:$false } $prop.DateTime = $ReturnVal } } if ($IncludeInput) { New-Object -TypeName psobject -Property $prop } else { Write-Output -inputobject $ReturnVal } } } end { Write-Verbose -Message "Ending [$($MyInvocation.Mycommand)]" } } #EndFunction ConvertTo-DateTime |