BirthdayInfo

struct BirthdayInfo {

            DateTime _today;
            DateTime _birthday;
            TimeSpan _fromToday;
            string _name;

            public BirthdayInfo(DateTime birthday,string name) {
                _today = DateTime.Now;
                _birthday = birthday;
                _fromToday = TimeSpan.Zero;
                _name = name;
            }
            public BirthdayInfo(DateTime birthday)
                : this(birthday,null) {
                _name = null;
            }

            public string Name {
                get { return _name; }
                set { _name = value; }
            }

            public DateTime Today {
                get { return _today; }
                set {
                    _today = value;
                    _fromToday = TimeSpan.Zero;
                }
            }
            public DateTime Birthday {
                get { return _birthday; }
                set {
                    _birthday = value;
                    _fromToday = TimeSpan.Zero;
                }
            }

            public int YearsFromToday {
                get {

                    DateTime thisYear = new DateTime(Today.Year,Birthday.Month,Birthday.Day,Birthday.Hour,Birthday.Minute,0);

                    if(Today > thisYear)
                        return thisYear.Year - Birthday.Year;
                    else
                        return (thisYear.Year - Birthday.Year) - 1;
                }
            }
            public int DaysFromToday {
                get {
                    return this.FromToday.Days;
                }
            }

            public int MinutesFromToday {
                get {
                    return (int)this.FromToday.TotalMinutes;
                }
            }

            public long SecondsFromToday {
                get {
                    return (long)this.FromToday.TotalSeconds;
                }
            }

            public TimeSpan FromToday {
                get {
                    if(_fromToday == TimeSpan.Zero)
                        _fromToday = _today.Subtract(_birthday);
                    return _fromToday;
                }
            }

            public override string ToString() {

                var info = this;
                StringBuilder builder = new StringBuilder();
                Action<string,object> output = (a,b) => builder.AppendLine(string.Format("{0,-20}  =  {1,20}",a,b));

                output("{0}'s BirthDay".FormatWith(info.Name),info.Birthday);
                output("Years since birth",info.YearsFromToday.ToString("#,#") + " years");
                output("Days since birth",info.DaysFromToday.ToString("#,#") + " days");
                output("Minutes since birth",info.DaysFromToday.ToString("#,#") + " minutes");
                output("Seconds since birth",info.SecondsFromToday.ToString("#,#") + " seconds");
                return builder.ToString();
            }
        }