The Sortable standard format specifier represents a custom date and time format string.
The format string is defined by the DateTimeFormatInfo.SortableDateTimePattern property.
The custom format string.
yyyy'-'MM'-'dd'T'HH':'mm':'ss
using System; class Demo { static void Main() { DateTime date = new DateTime(2018, 9, 5, 2, 12, 40); Console.WriteLine(date.ToString("s")); } }
2018-09-05T02:12:40