Formatting a datetime string in the YYYYMMDD format

I'm working with some strange APIs that requires the dates to be sent in the YYYYMMDD format.

I was thinking of doing something like this:

string date = string.Concat(DateTime.Now.Year, DateTime.Now.Month, DateTime.Now.Day);

Is there a better practice?

Another option would be to create an extension methods like:

public static class DateTimeExtensions
{
    public static string ToYMD(this DateTime theDate)
    {
        return theDate.ToString("yyyyMMdd");
    }

    public static string ToYMD(this DateTime? theDate)
    {
        return theDate.HasValue ? theDate.Value.ToYMD() : string.Empty;
    }
}

You would use it like:

var dateString = DateTime.Now.ToYMD();

The extension implemented also works for Nullable DateTime values.

If you are doing a lot of work with these 'yyyyMMdd' formatted DateTime values, the extension method has the benefit of less typing.

StackExchange Code Review Q#10250, answer score: 5