DelphiScript - String to DateTime/to 18 digit TimeStamp

Question

I'm trying to automate some of my recurring tasks. Amongst other jobs, i want to automate the LDAP Account Creation. Since we have employes with fixed-term employment contract, i want to automatically set the deactivation Date of these LDAP-Accounts to the last Day working.

Our tool where I do the automation supports DelphiScript, VBScript and JavaScript. Additionaly it would support PowerShell scripts.

I have a Date variable which i could declare as DateTime or as String. As DateTime it will look like 44366,3996712847 converted as a String it will look like 19.06.2021 09:36:35. In the end I need to convert one of these values as a 18 digit timestamp, so i can set a Account Expiration Date in LDAP.

A few years ago I did a lot in C#, but nothing with Delphi, JScript and VBScript. I'm also out of C# by now.

My approaches, where I first tried to Convert String to DateTime, look like this:

uses
  Classes, SysUtils;

var
  befristet: datetime;
  timestamp: string;    
               
begin  

  befristet := GetVarContent('DATA.Befristet');        
          
  timestamp := DateTimeToTimeStamp(befristet);  
                
  // Writing to Log
  LogMessage('VarContent: ' + befristet);
  
  // Returns 0 as script result
  Result := 0;
end;