While most commands deal with dates in a culture-specific format, care must be taken when passing dates as strings to parameters that cast to DateTime.

Casting to DateTime does not account for a cultural bias. For example, in the UK, the format dd/MM/yyyy is often used. Casting this format to DateTime will switch the format to MM/dd/yyyy (as used in the US):

$string = "11/10/2000"    # 11th October 2000 
[DateTime]$string         # 10th November 2000 

If a function is created that accepts DateTime as a parameter, the result may not be as expected, depending on the local culture:

function Test-DateTime { 
    param( 
        [DateTime]$Date 
    ) 
    $Date 
} 
Test-DateTime -Date "11/10/2000" 

It is possible to work around this problem using the Get-Date command, to ensure the culture specific conversion is more appropriately handled:

Test-DateTime -Date (Get-Date "11/10/2000")