c# data i czas dd/mm/rrrr gg:mm:ss
DateTime.Now.ToString("dd'/'MM'/'yyyy HH:mm:ss")
//output: 13/06/2020 13:05:21
Format daty i czasu.Teraz do rrrr-mm-dd z#
var dateString1 = DateTime.Now.ToString("yyyyMMdd");
var dateString2 = DateTime.Now.ToString("yyyy-MM-dd");
Console.WriteLine("yyyyMMdd " + dateString1);
Console.WriteLine("yyyy-MM-dd "+ dateString2);