C# - DateTime Runden

  /// <summary>
        /// The Rounding types
        /// </summary>
        public enum RoundType
        {
            /// <summary>
            /// Complete Hour
            /// </summary>
            Hour = 60,

            /// <summary>
            /// Half an Hour
            /// </summary>
            HalfHour = 30,

            /// <summary>
            /// 15 Miniutes
            /// </summary>
            QuaterHour = 15,

        }




        /// <summary>
        /// Roundes the given DateTime to the given Minutes Pattern (15,30,60...)
        /// </summary>
        /// <param name="source">DateTime which should be rounded</param>
        /// <param name="type">The Roundtype</param>
        public static System.DateTime Round(this System.DateTime source, RoundType type)
        {

            System.DateTime result = source;

            int minutes = Convert.ToInt32(type);
            int modulo;

            Math.DivRem(source.Minute, minutes, out modulo);


            if (modulo > 0)
            {
                if (modulo >= (minutes / 2))
                {
                    //Näher am oberen ende => nach utnen laufen
                    result = source.AddMinutes(minutes - modulo);
                }
                else
                {
                    //Wir sind näher am unteren ende => bis zur unteren basis laufen
                    result = source.AddMinutes(modulo * -1);

                }


                result = result.AddSeconds(source.Second * -1);
            }

            return result;
        }