using System.Globalization;
public static void Main()
var date = new DateTime(2000,1,12,1,1,1);
Console.WriteLine(date.ToString("%M/%d/yyyy h:mm:ss", new CultureInfo("es-ES")));
Console.WriteLine(date.ToString("%M/%d/yyyy h:mm:ss", new CultureInfo("ru-RU")));
Console.WriteLine(date.ToString("%M\\/%d\\/yyyy h:mm:ss", new CultureInfo("ru-RU")));