For the following code, I would expect result to equal 2, because the MSDN states that ‘d’ “Represents the day of the month as a number from 1 through 31. A single-digit day is formatted without a leading zero.”.
DateTime myDate = new DateTime( 2009, 6, 4 );
string result = myDate.ToString( "d" );
However, result is actually equal to ‘6/4/2009’ – which is the short-date format (which is also ‘d’). I could use ‘dd’, but that adds a leading zero, which I don’t want.
To indicate that this is a custom format specifier (in contrast to a standard format specifier), it must be two characters long. This can be accomplished by adding a space (which will show up in the output), or by including a percent sign before the single letter, like this:
See documentation