using System; public class MainClass{ /// <summary> /// Gets the days in year. /// </summary> /// <param name="date">The date.</param> /// <returns></returns> public static int GetDaysInYear(DateTime date) { if (date.Equals(DateTime.MinValue)) { return -1; } DateTime thisYear = new DateTime(date.Year, 1, 1); DateTime nextYear = new DateTime(date.Year + 1, 1, 1); return (nextYear - thisYear).Days; } }