private static DateTimeOffset entryDateAround(PlanetId star, Sign destSign, DateTimeOffset around)
{
Double speed = Planet.AverageSpeedOf(star);
int dayAdjustment = 0;
DateTimeOffset date = around.UtcDateTime.Date;
Position pos = CurrentEphemeris[date, star];
int dif = destSign.Order - Sign.SignOf(pos.Longitude).Order;
dayAdjustment = dif > 0 ? (int)((destSign.Order - Sign.SignOf(pos.Longitude).Order - 1) * 30 / speed)
: (int)((11 + destSign.Order - Sign.SignOf(pos.Longitude).Order) * 30 / speed);
do
{
date = date.AddDays(dayAdjustment);
pos = CurrentEphemeris[date, star];
dayAdjustment--;
} while (Sign.SignOf(pos.Longitude) != destSign.Previous);
if (Sign.SignOf(pos.Longitude) != destSign.Previous)
{
throw new Exception();
}
do
{
date = date.AddDays(1);
pos = CurrentEphemeris[date, star];
if (Sign.SignOf(pos.Longitude) == destSign)
{
return(date);
}
} while (true);
throw new Exception();
}