Update getSolarMidnight to use astronomical calc

Adding to the work done in fdf6c55 that supported astronomical noon, this change adds the same support to the experimental getSolarMidnight(). This allows calculations in the Arctic and Antarctic, and slightly improves accuracy.

Author: KosherJava

src/main/java/com/kosherjava/zmanim/ComplexZmanimCalendar.java

@@ -1,6 +1,6 @@
 /*
  * Zmanim Java API
- * Copyright (C) 2004-2022 Eliyahu Hershfeld
+ * Copyright (C) 2004-2023 Eliyahu Hershfeld
  *
  * This library is free software; you can redistribute it and/or modify it under the terms of the GNU Lesser General
  * Public License as published by the Free Software Foundation; either version 2.1 of the License, or (at your option)
@@ -10,7 +10,7 @@
  * warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU Lesser General Public License for more
  * details.
  * You should have received a copy of the GNU Lesser General Public License along with this library; if not, write to
- * the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA,
+ * the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA,
  * or connect to: https://www.gnu.org/licenses/old-licenses/lgpl-2.1.html
  */
 package com.kosherjava.zmanim;
@@ -106,7 +106,7 @@
  * <h2>Documentation from the {@link ZmanimCalendar} parent class</h2>
  * {@inheritDoc}
  * 
- * @author &copy; Eliyahu Hershfeld 2004 - 2022
+ * @author &copy; Eliyahu Hershfeld 2004 - 2023
  */
 public class ComplexZmanimCalendar extends ZmanimCalendar {
 
@@ -3797,9 +3797,7 @@ public Date getSofZmanBiurChametzMGA16Point1Degrees() {
 	public Date getSolarMidnight() {
 		ZmanimCalendar clonedCal = (ZmanimCalendar) clone();
 		clonedCal.getCalendar().add(Calendar.DAY_OF_MONTH, 1);
-		Date sunset = getSeaLevelSunset();
-		Date sunrise = clonedCal.getSeaLevelSunrise();
-		return getTimeOffset(sunset, getTemporalHour(sunset, sunrise) * 6);
+		return getTimeOffset(getChatzos(), clonedCal.getChatzos().getTime() - getChatzos().getTime());
 	}
 
 	/**
@@ -3996,6 +3994,7 @@ public Date getSofZmanBiurChametzBaalHatanya() {
 	 * sea level solar hours} after {@link #getSunriseBaalHatanya() <em>netz amiti</em> (sunrise)}. This calculation is based
 	 * on the opinion of the Baal Hatanya that the day is calculated from sunrise to sunset. This returns the time 6.5
 	 * * {@link #getShaahZmanisBaalHatanya()} after {@link #getSunriseBaalHatanya() <em>netz amiti</em> ("real" sunrise)}.
+	 * 
 	 * @see #getMinchaGedola(Date, Date)
 	 * @see #getShaahZmanisBaalHatanya()
 	 * @see #getMinchaKetanaBaalHatanya()