Formatting a DateTime value Day value

Question

Is there a simple method of displaying the day portion of a date in the format 1st, 2nd, 3rd,…? I suspect that there is no method of doing this through custom datetime formatstrings (I will be very happy to be wrong), so has anyone implemented a way of doing this?

Answer 1

This is the core logic for achieving this end:

string SuffixForDay(DateTime date) {
    switch (date.Day) {
        case 1:
        case 21:
        case 31:
            return "st";
        case 2:
        case 22:
            return "nd";
        case 3:
        case 23:
            return "rd";
        default:
            return "th";
     }
 }