Clean up tempBanCalendar

src/main/java/client/Character.java

@@ -167,7 +167,6 @@ import java.sql.Timestamp;
 import java.time.LocalDateTime;
 import java.util.ArrayList;
 import java.util.Arrays;
-import java.util.Calendar;
 import java.util.Collection;
 import java.util.Collections;
 import java.util.Comparator;
@@ -191,7 +190,6 @@ import java.util.concurrent.locks.ReentrantLock;
 import java.util.regex.Pattern;
 import java.util.stream.Collectors;
 
-import static java.util.concurrent.TimeUnit.DAYS;
 import static java.util.concurrent.TimeUnit.MINUTES;
 import static java.util.concurrent.TimeUnit.SECONDS;
 
@@ -10685,7 +10683,7 @@ public class Character extends AbstractCharacterObject {
     public int checkWorldTransferEligibility() {
         if (getLevel() < 20) {
             return 2;
-        } else if (getClient().getTempBanCalendar() != null && getClient().getTempBanCalendar().getTimeInMillis() + (int) DAYS.toMillis(30) < Calendar.getInstance().getTimeInMillis()) {
+        } else if (client.wasRecentlyBanned()) {
             return 3;
         } else if (isMarried()) {
             return 4;

src/main/java/client/Client.java

@@ -61,6 +61,8 @@ import java.sql.Connection;
 import java.sql.PreparedStatement;
 import java.sql.ResultSet;
 import java.sql.SQLException;
+import java.time.Duration;
+import java.time.Instant;
 import java.time.LocalDate;
 import java.util.Arrays;
 import java.util.Calendar;
@@ -118,7 +120,6 @@ public class Client extends ChannelInboundHandlerAdapter {
     private final Lock lock = new ReentrantLock(true);
     private final Lock announcerLock = new ReentrantLock(true);
     // thanks Masterrulax & try2hack for pointing out a bottleneck issue with shared locks, shavit for noticing an opportunity for improvement
-    private Calendar tempBanCalendar;
     private long lastNpcClick;
     private long lastPacket = System.currentTimeMillis();
 
@@ -500,8 +501,9 @@ public class Client extends ChannelInboundHandlerAdapter {
         return ++failedLoginAttempts < MAX_FAILED_LOGIN_ATTEMPTS;
     }
 
-    public Calendar getTempBanCalendar() {
-        return tempBanCalendar;
+    public boolean wasRecentlyBanned() {
+        Instant recentThreshold = Instant.now().minus(Duration.ofDays(30));
+        return account != null && account.bannedUntil() != null && account.bannedUntil().isAfter(recentThreshold);
     }
 
     public void updateHwid(Hwid hwid) {