public static void Main (string[] args) {

var today = DateTime.Now;

Console.WriteLine($"Using date and time: {today.ToString(@"yyyy-MM-dd\THH:mm:ss.fffffffK")}");

Console.WriteLine();

// Individual Format Specifiers

Console.WriteLine("Individual Format Specifiers");

Console.WriteLine($"1. {today.ToString("gg")}");

Console.WriteLine($"2. {today.ToString("''y")}");

Console.WriteLine($"3. {today.ToString("yy")}");

Console.WriteLine($"4. {today.ToString("yyy")}");

Console.WriteLine($"5. {today.ToString("yyyy")}");

Console.WriteLine($"6. {today.ToString("yyyyy")}");

Console.WriteLine($"7. {today.ToString("''M")}");

Console.WriteLine($"8. {today.ToString("MM")}");

Console.WriteLine($"9. {today.ToString("MMM")}");

Console.WriteLine($"10. {today.ToString("MMMM")}");

Console.WriteLine($"11. {today.ToString("''d")}");

Console.WriteLine($"12. {today.ToString("dd")}");

Console.WriteLine($"13. {today.ToString("ddd")}");

Console.WriteLine($"14. {today.ToString("dddd")}");

Console.WriteLine($"15. {today.ToString("''t")}");

Console.WriteLine($"16. {today.ToString("tt")}");

Console.WriteLine($"17. {today.ToString("''h")}");

Console.WriteLine($"18. {today.ToString("hh")}");

Console.WriteLine($"19. {today.ToString("''H")}");

Console.WriteLine($"20. {today.ToString("HH")}");

Console.WriteLine($"21. {today.ToString("''m")}");

Console.WriteLine($"22. {today.ToString("mm")}");

Console.WriteLine($"23. {today.ToString("''s")}");

Console.WriteLine($"24. {today.ToString("ss")}");

Console.WriteLine($"25. {today.ToString("''f")}");

Console.WriteLine($"26. {today.ToString("ff")}");

Console.WriteLine($"27. {today.ToString("fff")}");

Console.WriteLine($"28. {today.ToString("ffff")}");

Console.WriteLine($"29. {today.ToString("fffff")}");

Console.WriteLine($"30. {today.ToString("ffffff")}");

Console.WriteLine($"31. {today.ToString("fffffff")}");

Console.WriteLine($"32. {today.ToString("''F")}");

Console.WriteLine($"33. {today.ToString("FF")}");

Console.WriteLine($"34. {today.ToString("FFF")}");

Console.WriteLine($"35. {today.ToString("FFFF")}");

Console.WriteLine($"36. {today.ToString("FFFFF")}");

Console.WriteLine($"37. {today.ToString("FFFFFF")}");

Console.WriteLine($"38. {today.ToString("FFFFFFF")}");

Console.WriteLine($"39. {today.ToString("''K")}");

Console.WriteLine($"40. {today.ToString("''z")}");

Console.WriteLine($"41. {today.ToString("zz")}");

Console.WriteLine($"42. {today.ToString("zzz")}");

Console.WriteLine($"43. {today.ToString("''/")}");

Console.WriteLine($"44. {today.ToString("'':")}");

Console.WriteLine($"45. {today.ToString("'The date is' yyyy-MM-dd")}");

Console.WriteLine($"46. {today.ToString(@"\T\h\e \d\a\t\e \i\s yyyy-MM-dd")}");

Console.WriteLine();

// Combined Format Specifiers

Console.WriteLine("Combined Format Specifiers");

Console.WriteLine($"47. {today.ToString("yyyy-MM-dd")}");

Console.WriteLine($"48. {today.ToString("d MMMM yyyy")}");

Console.WriteLine($"49. {today.ToString("dddd, d MMMM yyyy")}");

Console.WriteLine($"50. {today.ToString("hh:mm:ss tt")}");

Console.WriteLine($"51. {today.ToString("HH:mm:ss.fffffff")}");

}