diff --git a/task01/src/com/example/task01/Logger.java b/task01/src/com/example/task01/Logger.java
new file mode 100644
index 00000000..fcd4f674
--- /dev/null
+++ b/task01/src/com/example/task01/Logger.java
@@ -0,0 +1,100 @@
+package com.example.task01;
+
+import java.util.ArrayList;
+import java.time.LocalDateTime;
+import java.time.format.DateTimeFormatter;
+
+public class Logger {
+
+    private static final DateTimeFormatter FORMATTER =
+            DateTimeFormatter.ofPattern("yyyy.MM.dd HH:mm:ss");
+
+    private String getCurrentDateTime() {
+        return LocalDateTime.now().format(FORMATTER);
+    }
+
+    public enum Level {
+        DEBUG,
+        INFO,
+        WARNING,
+        ERROR
+    }
+
+    private String name;
+    private static ArrayList<Logger> loggerList = new ArrayList<>();
+    private Level level;
+
+    public String getName(){
+        return name;
+    }
+
+    public Level getLevel(){
+        return level;
+    }
+
+    public void setLevel(Level level){
+        this.level = level;
+    }
+
+    public Logger(String name, Level level){
+        this.name = name;
+        this.level = level;
+        loggerList.add(this);
+    }
+
+    public static Logger getLogger(String name){
+        for (Logger e : loggerList){
+            if (e.getName().equals(name)) return e;
+        }
+
+        return new Logger(name, Level.DEBUG);
+    }
+
+    public void debug(String message){
+        log(Level.DEBUG, message);
+    }
+
+    public void debug(String pattern, Object... args){
+        log(Level.DEBUG, pattern, args);
+    }
+
+    public void info(String message){
+        log(Level.INFO, message);
+    }
+
+    public void info(String pattern, Object... args){
+        log(Level.INFO, pattern, args);
+    }
+
+    public void warning(String message){
+        log(Level.WARNING, message);
+    }
+
+    public void warning(String pattern, Object... args){
+        log(Level.WARNING, pattern, args);
+    }
+
+    public void error(String message){
+        log(Level.ERROR, message);
+    }
+
+    public void error(String pattern, Object... args){
+        log(Level.ERROR, pattern, args);
+    }
+
+    public void log(Level level, String message){
+        if (level.ordinal() >= this.level.ordinal()){
+            String datetime = getCurrentDateTime();
+            String logMessage = String.format("[%s] %s %s - %s",
+                    level, datetime, name, message);
+
+            System.out.println(logMessage);
+        }
+    }
+
+    public void log(Level level, String pattern, Object... args){
+        if (level.ordinal() >= this.level.ordinal()){
+            System.out.println(String.format(pattern, args));
+        }
+    }
+}
diff --git a/task02/src/com/example/task02/DiscountBill.java b/task02/src/com/example/task02/DiscountBill.java
new file mode 100644
index 00000000..65319415
--- /dev/null
+++ b/task02/src/com/example/task02/DiscountBill.java
@@ -0,0 +1,22 @@
+package com.example.task02;
+
+public class DiscountBill extends Bill {
+    private final double discount;
+
+    public DiscountBill(double discount){
+        this.discount = discount;
+    }
+
+    @Override
+    public long getPrice(){
+        return (long) (super.getPrice() - super.getPrice() * this.discount);
+    }
+
+    public double getDiscount(){
+        return this.discount * 100;
+    }
+
+    public long getAbsoluteDiscount(){
+        return super.getPrice() - this.getPrice();
+    }
+}
diff --git a/task03/src/com/example/task03/Hours.java b/task03/src/com/example/task03/Hours.java
new file mode 100644
index 00000000..61eb972d
--- /dev/null
+++ b/task03/src/com/example/task03/Hours.java
@@ -0,0 +1,29 @@
+package com.example.task03;
+
+public class Hours implements TimeUnit{
+    private final long amount;
+
+    public Hours(long amount) {
+        this.amount = amount;
+    }
+
+    @Override
+    public long toMillis() {
+        return amount * 60 * 60 * 1000;
+    }
+
+    @Override
+    public long toSeconds() {
+        return amount * 60 * 60;
+    }
+
+    @Override
+    public long toMinutes() {
+        return amount * 60;
+    }
+
+    @Override
+    public long getHours() {
+        return amount;
+    }
+}
diff --git a/task03/src/com/example/task03/Milliseconds.java b/task03/src/com/example/task03/Milliseconds.java
index 5115bc7d..1774a71f 100644
--- a/task03/src/com/example/task03/Milliseconds.java
+++ b/task03/src/com/example/task03/Milliseconds.java
@@ -18,11 +18,16 @@ public long toMillis() {
 
     @Override
     public long toSeconds() {
-        return amount / 1000;
+        return Math.round(amount / 1000.0);
     }
 
     @Override
     public long toMinutes() {
-        return amount / 1000 * 60;
+        return Math.round(amount / (1000.0 * 60.0));
+    }
+
+    @Override
+    public long getHours() {
+        return Math.round(amount / (1000.0 * 60.0 * 60.0));
     }
 }
diff --git a/task03/src/com/example/task03/Minutes.java b/task03/src/com/example/task03/Minutes.java
index d6fa0594..d1f755bb 100644
--- a/task03/src/com/example/task03/Minutes.java
+++ b/task03/src/com/example/task03/Minutes.java
@@ -1,27 +1,33 @@
 package com.example.task03;
 
 public class Minutes implements TimeUnit {
+    private final long amount;
 
     public Minutes(long amount) {
         // TODO: реализовать
-        throw new UnsupportedOperationException();
+        this.amount = amount;
     }
 
     @Override
     public long toMillis() {
         // TODO: реализовать
-        throw new UnsupportedOperationException();
+        return amount * 60 * 1000;
     }
 
     @Override
     public long toSeconds() {
         // TODO: реализовать
-        throw new UnsupportedOperationException();
+        return amount * 60;
     }
 
     @Override
     public long toMinutes() {
         // TODO: реализовать
-        throw new UnsupportedOperationException();
+        return amount;
+    }
+
+    @Override
+    public long getHours() {
+        return Math.round(amount / 60.0);
     }
 }
diff --git a/task03/src/com/example/task03/Seconds.java b/task03/src/com/example/task03/Seconds.java
index ce6bc213..008f5b25 100644
--- a/task03/src/com/example/task03/Seconds.java
+++ b/task03/src/com/example/task03/Seconds.java
@@ -23,6 +23,11 @@ public long toSeconds() {
 
     @Override
     public long toMinutes() {
-        return Math.round(amount / 60);
+        return Math.round(amount / 60.0);
+    }
+
+    @Override
+    public long getHours() {
+        return Math.round(amount / (60.0 * 60.0));
     }
 }
diff --git a/task03/src/com/example/task03/TimeUnit.java b/task03/src/com/example/task03/TimeUnit.java
index 3b123fb8..907bda1f 100644
--- a/task03/src/com/example/task03/TimeUnit.java
+++ b/task03/src/com/example/task03/TimeUnit.java
@@ -28,4 +28,11 @@ public interface TimeUnit {
      */
     long toMinutes();
 
+    /**
+     * Возвращает продолжительность текущего интервала, пересчитанного в часах.
+     * При необходимости округлять по обычным правилам округления (число, меньшее 0.5 переходит в 0, большее или равное - в 1)
+     *
+     * @return количество часов в текущем интервале
+     */
+    long getHours();
 }
diff --git a/task03/src/com/example/task03/TimeUnitUtils.java b/task03/src/com/example/task03/TimeUnitUtils.java
index 790f8850..6397da86 100644
--- a/task03/src/com/example/task03/TimeUnitUtils.java
+++ b/task03/src/com/example/task03/TimeUnitUtils.java
@@ -15,6 +15,14 @@ public static Milliseconds toMillis(Seconds seconds) {
         return new Milliseconds(seconds.toMillis());
     }
 
+    public static Milliseconds toMillis(Minutes minutes) {
+        return new Milliseconds(minutes.toMillis());
+    }
+
+    public static Milliseconds toMillis(Hours hours) {
+        return new Milliseconds(hours.toMillis());
+    }
+
     /**
      * Конвертирует интервал в миллисекундах в интервал в секундах
      *
@@ -24,4 +32,48 @@ public static Milliseconds toMillis(Seconds seconds) {
     public static Seconds toSeconds(Milliseconds millis) {
         return new Seconds(millis.toSeconds());
     }
+
+    public static Seconds toSeconds(Minutes minutes) {
+        return new Seconds(minutes.toSeconds());
+    }
+
+    public static Seconds toSeconds(Hours hours) {
+        return new Seconds(hours.toSeconds());
+    }
+
+    /**
+     * Конвертирует интервал в миллисекундах в интервал в минутах
+     *
+     * @param millis интервал в миллисекундах
+     * @return интервал в минутах
+     */
+    public static Minutes toMinutes(Milliseconds millis) {
+        return new Minutes(millis.toMinutes());
+    }
+
+    public static Minutes toMinutes(Seconds seconds) {
+        return new Minutes(seconds.toMinutes());
+    }
+
+    public static Minutes toMinutes(Hours hours) {
+        return new Minutes(hours.toMinutes());
+    }
+
+    /**
+     * Конвертирует интервал в миллисекундах в интервал в часах
+     *
+     * @param millis интервал в миллисекундах
+     * @return интервал в часах
+     */
+    public static Hours getHours(Milliseconds millis) {
+        return new Hours(millis.getHours());
+    }
+
+    public static Hours getHours(Seconds seconds) {
+        return new Hours(seconds.getHours());
+    }
+
+    public static Hours getHours(Minutes minutes) {
+        return new Hours(minutes.getHours());
+    }
 }
diff --git a/task04/src/com/example/task04/ConsoleHandler.java b/task04/src/com/example/task04/ConsoleHandler.java
new file mode 100644
index 00000000..b0df320e
--- /dev/null
+++ b/task04/src/com/example/task04/ConsoleHandler.java
@@ -0,0 +1,8 @@
+package com.example.task04;
+
+public class ConsoleHandler implements MessageHandler{
+    @Override
+    public void log(String message){
+        System.out.println(message);
+    }
+}
diff --git a/task04/src/com/example/task04/FileHandler.java b/task04/src/com/example/task04/FileHandler.java
new file mode 100644
index 00000000..8c226e2c
--- /dev/null
+++ b/task04/src/com/example/task04/FileHandler.java
@@ -0,0 +1,32 @@
+package com.example.task04;
+
+import java.nio.file.Files;
+import java.nio.file.Path;
+import java.nio.file.Paths;
+import java.io.IOException;
+import java.nio.file.StandardOpenOption;
+
+public class FileHandler implements MessageHandler {
+    private final Path filePath;
+
+    public FileHandler(String filePath) {
+        this.filePath = Paths.get(filePath);
+        try {
+            if (this.filePath.getParent() != null) {
+                Files.createDirectories(this.filePath.getParent());
+            }
+        } catch (IOException e) {
+            throw new RuntimeException("Cannot create directories", e);
+        }
+    }
+
+    @Override
+    public void log(String message) {
+        try {
+            Files.write(filePath, (message + System.lineSeparator()).getBytes(),
+                    StandardOpenOption.CREATE, StandardOpenOption.APPEND);
+        } catch (IOException e) {
+            throw new RuntimeException("Cannot write to file: " + filePath, e);
+        }
+    }
+}
diff --git a/task04/src/com/example/task04/Logger.java b/task04/src/com/example/task04/Logger.java
new file mode 100644
index 00000000..ec628612
--- /dev/null
+++ b/task04/src/com/example/task04/Logger.java
@@ -0,0 +1,119 @@
+package com.example.task04;
+
+import java.time.LocalDateTime;
+import java.time.format.DateTimeFormatter;
+import java.util.ArrayList;
+import java.util.List;
+
+public class Logger {
+
+    private static final DateTimeFormatter FORMATTER =
+            DateTimeFormatter.ofPattern("yyyy.MM.dd HH:mm:ss");
+
+    private String getCurrentDateTime() {
+        return LocalDateTime.now().format(FORMATTER);
+    }
+
+    public enum Level {
+        DEBUG,
+        INFO,
+        WARNING,
+        ERROR
+    }
+
+    private String name;
+    private static ArrayList<Logger> loggerList = new ArrayList<>();
+    private Level level;
+    private List<MessageHandler> handlers = new ArrayList<>();
+
+    public String getName(){
+        return name;
+    }
+
+    public Level getLevel(){
+        return level;
+    }
+
+    public void setLevel(Level level){
+        this.level = level;
+    }
+
+    public void addHandler(MessageHandler handler) {
+        handlers.add(handler);
+    }
+
+    public void removeHandler(MessageHandler handler) {
+        handlers.remove(handler);
+    }
+
+    public List<MessageHandler> getHandlers() {
+        return new ArrayList<>(handlers);
+    }
+
+    public Logger(String name, Level level){
+        this.name = name;
+        this.level = level;
+        loggerList.add(this);
+    }
+
+    public static Logger getLogger(String name){
+        for (Logger e : loggerList){
+            if (e.getName().equals(name)) return e;
+        }
+
+        return new Logger(name, Level.DEBUG);
+    }
+
+    private String formatMessage(Level level, String message) {
+        return String.format("[%s] %s %s - %s",
+                level, getCurrentDateTime(), name, message);
+    }
+
+    private void handleLog(Level level, String formattedMessage) {
+        if (level.ordinal() >= this.level.ordinal()) {
+            for (MessageHandler handler : handlers) {
+                handler.log(formattedMessage);
+            }
+        }
+    }
+
+    public void debug(String message){
+        log(Level.DEBUG, message);
+    }
+
+    public void debug(String pattern, Object... args){
+        log(Level.DEBUG, pattern, args);
+    }
+
+    public void info(String message){
+        log(Level.INFO, message);
+    }
+
+    public void info(String pattern, Object... args){
+        log(Level.INFO, pattern, args);
+    }
+
+    public void warning(String message){
+        log(Level.WARNING, message);
+    }
+
+    public void warning(String pattern, Object... args){
+        log(Level.WARNING, pattern, args);
+    }
+
+    public void error(String message){
+        log(Level.ERROR, message);
+    }
+
+    public void error(String pattern, Object... args){
+        log(Level.ERROR, pattern, args);
+    }
+
+    public void log(Level level, String message){
+        handleLog(level, formatMessage(level, message));
+    }
+
+    public void log(Level level, String pattern, Object... args){
+        handleLog(level, formatMessage(level, String.format(pattern, args)));
+    }
+}
diff --git a/task04/src/com/example/task04/MemoryHandler.java b/task04/src/com/example/task04/MemoryHandler.java
new file mode 100644
index 00000000..b274b2af
--- /dev/null
+++ b/task04/src/com/example/task04/MemoryHandler.java
@@ -0,0 +1,37 @@
+package com.example.task04;
+
+import java.util.ArrayList;
+import java.util.List;
+
+public class MemoryHandler implements MessageHandler {
+    private final MessageHandler targetHandler;
+    private final int bufferSize;
+    private final List<String> buffer;
+
+    public MemoryHandler(MessageHandler targetHandler, int bufferSize) {
+        this.targetHandler = targetHandler;
+        this.bufferSize = bufferSize;
+        this.buffer = new ArrayList<>(bufferSize);
+    }
+
+    @Override
+    public void log(String message) {
+        synchronized (buffer) {
+            buffer.add(message);
+            if (buffer.size() >= bufferSize) {
+                flush();
+            }
+        }
+    }
+
+    public void flush() {
+        synchronized (buffer) {
+            if (!buffer.isEmpty()) {
+                for (String message : buffer) {
+                    targetHandler.log(message);
+                }
+                buffer.clear();
+            }
+        }
+    }
+}
diff --git a/task04/src/com/example/task04/MessageHandler.java b/task04/src/com/example/task04/MessageHandler.java
new file mode 100644
index 00000000..13beca02
--- /dev/null
+++ b/task04/src/com/example/task04/MessageHandler.java
@@ -0,0 +1,5 @@
+package com.example.task04;
+
+public interface MessageHandler {
+    void log(String message);
+}
diff --git a/task04/src/com/example/task04/RotationFileHandler.java b/task04/src/com/example/task04/RotationFileHandler.java
new file mode 100644
index 00000000..67f6eaba
--- /dev/null
+++ b/task04/src/com/example/task04/RotationFileHandler.java
@@ -0,0 +1,52 @@
+package com.example.task04;
+
+import java.nio.file.StandardOpenOption;
+import java.time.temporal.ChronoUnit;
+import java.time.format.DateTimeFormatter;
+import java.time.LocalDateTime;
+import java.nio.file.Files;
+import java.nio.file.Path;
+import java.nio.file.Paths;
+import java.io.IOException;
+
+public class RotationFileHandler implements MessageHandler {
+    private final String basePath;
+    private final ChronoUnit rotationUnit;
+    private final DateTimeFormatter timeFormatter;
+
+    public RotationFileHandler(String basePath, ChronoUnit rotationUnit) {
+        this.basePath = basePath;
+        this.rotationUnit = rotationUnit;
+        this.timeFormatter = getDateTimeFormatter(rotationUnit);
+    }
+
+    private DateTimeFormatter getDateTimeFormatter(ChronoUnit rotationUnit) {
+        switch (rotationUnit) {
+            case HOURS: return DateTimeFormatter.ofPattern("yyyy-MM-dd-HH");
+            case DAYS: return DateTimeFormatter.ofPattern("yyyy-MM-dd");
+            case MONTHS: return DateTimeFormatter.ofPattern("yyyy-MM");
+            default: return DateTimeFormatter.ofPattern("yyyy-MM-dd_HH-mm-ss");
+        }
+    }
+
+    private Path getCurrentFilePath() {
+        LocalDateTime now = LocalDateTime.now().truncatedTo(rotationUnit);
+        String filename = basePath + "_" + now.format(timeFormatter) + ".log";
+        return Paths.get(filename);
+    }
+
+    @Override
+    public void log(String message) {
+        Path currentFilePath = getCurrentFilePath();
+
+        try {
+            if (currentFilePath.getParent() != null) {
+                Files.createDirectories(currentFilePath.getParent());
+            }
+            Files.write(currentFilePath, (message + System.lineSeparator()).getBytes(),
+                    StandardOpenOption.CREATE, StandardOpenOption.APPEND);
+        } catch (IOException e) {
+            throw new RuntimeException("Cannot write to file: " + currentFilePath, e);
+        }
+    }
+}
diff --git a/task04/src/com/example/task04/Task04Main.java b/task04/src/com/example/task04/Task04Main.java
index 55917a30..c3139316 100644
--- a/task04/src/com/example/task04/Task04Main.java
+++ b/task04/src/com/example/task04/Task04Main.java
@@ -1,5 +1,7 @@
 package com.example.task04;
 
+import java.time.temporal.ChronoUnit;
+
 public class Task04Main {
     public static void main(String[] args) {