Mine windows are set by the nation's WOO.

src/engine/objects/Mine.java

@@ -285,7 +285,7 @@ public class Mine extends AbstractGameObject {
 
         if (mineOwnerGuild.isErrant() == false && mine.isActive == false) {
 
-            int guildWOO = mineOwnerGuild.getMineTime();
+            int guildWOO = mineOwnerGuild.getNation().getMineTime();
             LocalDateTime guildMineTime = mineOpenTime.withHour(guildWOO);
 
             if (mineOpenTime.isAfter(guildMineTime))
@@ -295,7 +295,6 @@ public class Mine extends AbstractGameObject {
 
         }
 
-
         writer.putLocalDateTime(mineOpenTime);
         writer.putLocalDateTime(mineOpenTime.plusHours(1));
         writer.put(mine.isActive ? (byte) 0x01 : (byte) 0x00);

src/engine/workthreads/HourlyJobThread.java

@@ -113,7 +113,7 @@ public class HourlyJobThread implements Runnable {
 
 					// Open Mines with a current guild hour
 
-					if (mine.getOwningGuild().getMineTime() ==
+					if (mine.getOwningGuild().getNation().getMineTime() ==
 						LocalDateTime.now().getHour()) {
 						mine.handleStartMineWindow();
 						Mine.setLastChange(System.currentTimeMillis());