gistfile1.cs

public static string BuildDateDirectory()
{
    string year = DateTime.Now.Year.ToString();
    string month = DateTime.Now.Month.ToString();
    string day = DateTime.Now.Day.ToString();
    string hour = DateTime.Now.Hour.ToString();
    string minute = DateTime.Now.Minute.ToString();

    if (month.Length == 1)
        month = string.Format("0{0}", month);
    if (day.Length == 1)
        day = string.Format("0{0}", day);
    if (hour.Length == 1)
        hour = string.Format("0{0}", hour);
    if (minute.Length == 1)
        minute = string.Format("0{0}", minute);

    return string.Format("{0}-{1}-{2} {3}{4}", year, month, day, hour, minute);
}

VERSUS

DateTime.Now.ToString("yyyy-MM-dd HHmm");