class DateCheckFilter extends AbstractDateCheckFilter {

  @Override
  protected Calendar getCalendar() {
    return Calendar.getInstance(Locale.forLanguageTag("pl"));
  }

  @SuppressWarnings("ControlFlowStatementWithoutBraces")
  @Override
  protected int getDayOfWeek(String dayStr) {
    String day = dayStr.toLowerCase();
    if (day.startsWith("pon")) return Calendar.MONDAY;
    if (day.startsWith("wt")) return Calendar.TUESDAY;
    if (day.startsWith("śr")) return Calendar.WEDNESDAY;
    if (day.startsWith("czw")) return Calendar.THURSDAY;
    if (day.equals("pt") || day.startsWith("piątk") || day.equals("piątek")) return Calendar.FRIDAY;
    if (day.startsWith("sob")) return Calendar.SATURDAY;
    if (day.startsWith("niedz")) return Calendar.SUNDAY;
    throw new RuntimeException("Could not find day of week for '" + dayStr + "'");
  }

  @Override
  protected String getDayOfWeek(Calendar date) {
    return date.getDisplayName(Calendar.DAY_OF_WEEK, Calendar.LONG, Locale.forLanguageTag("pl"));
  }

  @SuppressWarnings({"ControlFlowStatementWithoutBraces", "MagicNumber"})
  @Override
  protected int getMonth(String monthStr) {<FILL_FUNCTION_BODY>}
}

    String mon = monthStr.toLowerCase();
    if (mon.equals("stycznia") || monthStr.equals("I")) return 1;
    if (mon.equals("lutego") || monthStr.equals("II")) return 2;
    if (mon.equals("marca") || monthStr.equals("III")) return 3;
    if (mon.equals("kwietnia") || monthStr.equals("IV")) return 4;
    if (mon.equals("maja") || monthStr.equals("V")) return 5;
    if (mon.equals("czerwca") || monthStr.equals("VI")) return 6;
    if (mon.equals("lipca") || monthStr.equals("VII")) return 7;
    if (mon.equals("sierpnia") || monthStr.equals("VIII")) return 8;
    if (mon.equals("września") || monthStr.equals("IX")) return 9;
    if (mon.equals("października") || monthStr.equals("X")) return 10;
    if (mon.equals("listopada") || monthStr.equals("XI")) return 11;
    if (mon.equals("grudnia") || monthStr.equals("XII")) return 12;
    throw new RuntimeException("Could not find month '" + monthStr + "'");
  
<methods>public non-sealed void <init>() ,public org.languagetool.rules.RuleMatch acceptRuleMatch(org.languagetool.rules.RuleMatch, Map<java.lang.String,java.lang.String>, int, org.languagetool.AnalyzedTokenReadings[], List<java.lang.Integer>) <variables>protected static final java.util.regex.Pattern DAY_OF_MONTH_PATTERN,private static final Logger logger