Datetime example

System.Globalization.CultureInfo culture = new System.Globalization.CultureInfo("en-GB"); // UK date format (DD/MM/YY)
string dateAndTime = System.DateTime.Now.ToString(culture); // Get date and time (DD/MM/YY hh:mm:ss)
string date = dateAndTime.Split(' ')[0]; // Get just date
string fileNameFriendlyDate = date.Replace('/', '-'); // Replace '/' with '-' because '/' is used for file path
Debug.Log(fileNameFriendlyDate); // Output: "16-11-2017"