public static DateTimeSpan CalulateDateTimeSpan(this DateTime date, DateTime dateToCompare) { return(DateTimeSpan.CompareDates(date, dateToCompare)); }
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); }