Expanded Kirks struct with ToString(format) and Duration(long ms)
public struct DateTimeSpan{ private readonly int years; private readonly int months; private readonly int days; private readonly int hours; private readonly int minutes; private readonly int seconds; private readonly int milliseconds; public DateTimeSpan(int years, int months, int days, int hours, int minutes, int seconds, int milliseconds) { this.years = years; this.months = months; this.days = days; this.hours = hours; this.minutes = minutes; this.seconds = seconds; this.milliseconds = milliseconds; } public int Years { get { return years; } } public int Months { get { return months; } } public int Days { get { return days; } } public int Hours { get { return hours; } } public int Minutes { get { return minutes; } } public int Seconds { get { return seconds; } } public int Milliseconds { get { return milliseconds; } } enum Phase { Years, Months, Days, Done } public string ToString(string format) { format = format.Replace("YYYY", Years.ToString()); format = format.Replace("MM", Months.ToString()); format = format.Replace("DD", Days.ToString()); format = format.Replace("hh", Hours.ToString()); format = format.Replace("mm", Minutes.ToString()); format = format.Replace("ss", Seconds.ToString()); format = format.Replace("ms", Milliseconds.ToString()); return format; } public static DateTimeSpan Duration(long ms) { DateTime dt = new DateTime(); return CompareDates(dt, dt.AddMilliseconds(ms)); } public static DateTimeSpan CompareDates(DateTime date1, DateTime date2) { if (date2 < date1) { var sub = date1; date1 = date2; date2 = sub; } DateTime current = date1; int years = 0; int months = 0; int days = 0; Phase phase = Phase.Years; DateTimeSpan span = new DateTimeSpan(); while (phase != Phase.Done) { switch (phase) { case Phase.Years: if (current.AddYears(years + 1) > date2) { phase = Phase.Months; current = current.AddYears(years); } else { years++; } break; case Phase.Months: if (current.AddMonths(months + 1) > date2) { phase = Phase.Days; current = current.AddMonths(months); } else { months++; } break; case Phase.Days: if (current.AddDays(days + 1) > date2) { current = current.AddDays(days); var timespan = date2 - current; span = new DateTimeSpan(years, months, days, timespan.Hours, timespan.Minutes, timespan.Seconds, timespan.Milliseconds); phase = Phase.Done; } else { days++; } break; } } return span; }}