Test cases for parsing UTC dates to a datetime that can be used to compare datetime values in an sql database where all datetime columns are in UTC but without timezone specifier

test-parsedate.ps1

param( [switch] $passOnly )

function TypeConvert-DateTime { 
	param( $dtString ) 
	[ScriptBlock]::Create(@"
  [System.ComponentModel.TypeDescriptor]::GetConverter( [datetime] ).ConvertFrom( "$dtString" )
"@ )
}
function ParseAdjustUtc-DateTime { 
	param( $dtString ) 
	[ScriptBlock]::Create(@"
  [datetime]::Parse( "$dtString", 
                     [cultureinfo]::InvariantCulture, 
                     [System.Globalization.DateTimeStyles]::AdjustToUniversal ) 
"@ )
}
function DefaultParse-DateTime {
	param( $dtString ) 
	[ScriptBlock]::Create("  [datetime]::Parse( ""$dtString"" ) " )
}
function CastTo-DateTime {
	param( $dtString ) 
	[ScriptBlock]::Create("  [datetime]""$dtString"" " )
}
function new-utcdatetime {
	param( [int] $year, [int] $month, [int] $day, 
		[int] $hour = 0, [int] $minute = 0, [int] $second = 0, [int] $millisecond = 0
		) 
	[ScriptBlock]::Create("new-object datetime($year, $month, $day, $hour, $minute, $second, $millisecond, [DateTimeKind]::Utc)")
}
function print( $expected, $actual ) {
	$actualDt = & $actual
	$expectedDt = & $expected
	$color = "red"
	$result = "  ..fails!"
	if( $actualDt -eq $expectedDt ) {
		$color = "green"
		$result = "  ..works!"
	} elseif( $passOnly ) {
		return
	}
	Write-Host ""
	$actual | out-host
	Write-Host -nonewline -foregroundcolor $color $result
	Write-Host -foregroundcolor gray ( " Got: {0:yyyy-MM-dd HH:mm:ss.fff} (Kind: {1}, Diff: {2})`r`n" -f $actualDt, $actualDt.Kind, [timespan]($expectedDt.Ticks - $actualDt.Ticks))
}
function expect( [string] $date, [ScriptBlock] $toEqual ) {
	Write-Host -foregroundcolor gray ( "Input   : ""{0}""" -f $date )
	Write-Host -foregroundcolor gray ( "Expected: {0}" -f $toEqual )

	print $toEqual (TypeConvert-DateTime $date)
	print $toEqual (DefaultParse-DateTime $date)
	print $toEqual (CastTo-DateTime $date)
	print $toEqual (ParseAdjustUtc-DateTime $date)
	new-object string("=", 96) | out-host
}

expect "2015-04-01 01:02:03.400-05:00" -toEqual (new-utcdatetime 2015 4 1 6 2 3 400)
expect "2015-04-01T00:00Z" -toEqual (new-utcdatetime 2015 4 1)
expect "2015-04-01 00:00Z" -toEqual (new-utcdatetime 2015 4 1)
expect "2015-04-01T02:00" -toEqual (new-utcdatetime 2015 4 1 2 0)
expect "2015-04-01T02:00Z" -toEqual (new-utcdatetime 2015 4 1 2 0)