How to convert Java.Util.Date to System.DateTime

Do this:

public DateTime ConvertDateToDateTime(Date date)
{
    SimpleDateFormat dateFormat = new SimpleDateFormat("YYYY-MM-dd hh:mm:ss");
    String dateFormated = dateFormat.format(date);

   return new DateTime(dateFormated);
}

java.util.Date has a getTime() method, which returns the date as a millisecond value. The value is the number of milliseconds since Jan. 1, 1970, midnight GMT.

With that knowledge, you can construct a System.DateTime, that matches this value like so:

public DateTime FromUnixTime(long unixTimeMillis)
{
    var epoch = new DateTime(1970, 1, 1, 0, 0, 0, DateTimeKind.Utc);
    return epoch.AddMilliseconds(unixTimeMillis);
}

(method taken from this answer)