You can escape it using a backslash which you will have to escape. Either
return dt.ToString(@"MMM d \'yy 'at' H:mmm");
or
return dt.ToString("MMM d \\'yy 'at' H:mmm");
You can escape it using a backslash which you will have to escape. Either
return dt.ToString(@"MMM d \'yy 'at' H:mmm");
or
return dt.ToString("MMM d \\'yy 'at' H:mmm");