public void TestDaysDifference()
{
double totalElapsedTime = TimeConstants.SecondsPerDay * 2.5;
double totalElapsedTimeDays = totalElapsedTime / TimeConstants.SecondsPerDay;
//Test same time standard, both safe
JulianDate first = new JulianDate(2451545.0);
JulianDate second = first + Duration.FromSeconds(totalElapsedTime);
Assert.AreEqual(totalElapsedTimeDays, first.DaysDifference(second));
Assert.AreEqual((second - first).TotalSeconds / TimeConstants.SecondsPerDay, first.DaysDifference(second));
//Test same time standard, both unsafe
first = new JulianDate(2451545.0, TimeStandard.CoordinatedUniversalTime);
second = first + Duration.FromSeconds(totalElapsedTime);
second = new JulianDate(second.Day, second.SecondsOfDay, TimeStandard.CoordinatedUniversalTime);
Assert.AreEqual(totalElapsedTimeDays, first.DaysDifference(second));
Assert.AreEqual((second - first).TotalSeconds / TimeConstants.SecondsPerDay, first.DaysDifference(second));
//Test diff time standard, one safe, one unsafe
first = new JulianDate(2451545.0);
second = first + Duration.FromSeconds(totalElapsedTime);
JulianDate secondDiffStandard = second.ToTimeStandard(TimeStandard.CoordinatedUniversalTime);
Assert.AreEqual(totalElapsedTimeDays, first.DaysDifference(secondDiffStandard));
Assert.AreEqual((secondDiffStandard - first).TotalSeconds / TimeConstants.SecondsPerDay, first.DaysDifference(secondDiffStandard));
first = JulianDate.MinValue;
second = JulianDate.MaxValue;
Assert.AreEqual((long)int.MaxValue - int.MinValue, first.DaysDifference(second));
}