/// <summary>
/// Set the time horizon start time for an <see cref="ITimeSet"/>, assuming it is a
/// <see cref="TimeSet"/>, if not, an exception is thrown. End time is unchanged,
/// i.e. the duration will change.
/// </summary>
/// <param name="timeSet">Time set to update</param>
/// <param name="timeHorizonStart">New time horizon start time</param>
public static void SetTimeHorizonStart(this ITimeSet timeSet, ITime timeHorizonStart)
{
double startMjd = timeHorizonStart.StampAsModifiedJulianDay;
double endMjd = timeSet.TimeHorizon.EndStampAsModifiedJulianDay();
ITime newHorizon = new Time(startMjd, endMjd - startMjd);
timeSet.SetTimeHorizon(newHorizon);
}
