Gets the grade level of the person based on their High School graduation date. The grade level is -1 for prekindergarten, 0 for kindergarten, 1 for first grade, etc. and null if they do not have a graduation date set.

CalculateGrade.cs

        /// <summary>
        /// Gets the grade level of the person based on their High School graduation date.
        /// </summary>
        /// <value>
        /// The grade level (-1 for prekindergarten, 0 for kindergarten, 1 for first grade, etc.) or null if they have no graduation date.
        /// </value>
        [NotMapped]
        [DataMember]
        [MergeField]
        public virtual int? Grade
        {
            get
            {
                if ( ! GraduationDate.HasValue )
                {
                    return null;
                }
                else
                {
                    // Is it before the promotion date?
                    // TODO: change next line to use a "PromotionDate" instead pulling the mm and dd from the GraduationDate.
                    DateTime promotionDate = new DateTime( DateTime.Now.Year, GraduationDate.Value.Month, GraduationDate.Value.Day );

                    var gradeMaxFactorReactor = ( DateTime.Now < promotionDate ) ? 12 : 13;
                    return gradeMaxFactorReactor - ( GraduationDate.Value.Year - DateTime.Now.Year );
                }
            }
        }