diff --git a/config.json b/config.json
index 484d807d0..92dfd05b1 100644
--- a/config.json
+++ b/config.json
@@ -1211,6 +1211,20 @@
         ],
         "difficulty": 6
       },
+      {
+        "slug": "baffling-birthdays",
+        "name": "Baffling Birthdays",
+        "uuid": "b534049a-5920-4906-9091-0fa6d81a3636",
+        "practices": [],
+        "prerequisites": [
+          "for-loops",
+          "lists",
+          "sets",
+          "randomness",
+          "datetime"
+        ],
+        "difficulty": 6
+      },
       {
         "slug": "bank-account",
         "name": "Bank Account",
diff --git a/exercises/practice/baffling-birthdays/.docs/instructions.md b/exercises/practice/baffling-birthdays/.docs/instructions.md
new file mode 100644
index 000000000..a01ec8679
--- /dev/null
+++ b/exercises/practice/baffling-birthdays/.docs/instructions.md
@@ -0,0 +1,23 @@
+# Instructions
+
+Your task is to estimate the birthday paradox's probabilities.
+
+To do this, you need to:
+
+- Generate random birthdates.
+- Check if a collection of randomly generated birthdates contains at least two with the same birthday.
+- Estimate the probability that at least two people in a group share the same birthday for different group sizes.
+
+~~~~exercism/note
+A birthdate includes the full date of birth (year, month, and day), whereas a birthday refers only to the month and day, which repeat each year.
+Two birthdates with the same month and day correspond to the same birthday.
+~~~~
+
+~~~~exercism/caution
+The birthday paradox assumes that:
+
+- There are 365 possible birthdays (no leap years).
+- Each birthday is equally likely (uniform distribution).
+
+Your implementation must follow these assumptions.
+~~~~
diff --git a/exercises/practice/baffling-birthdays/.docs/introduction.md b/exercises/practice/baffling-birthdays/.docs/introduction.md
new file mode 100644
index 000000000..97dabd1e6
--- /dev/null
+++ b/exercises/practice/baffling-birthdays/.docs/introduction.md
@@ -0,0 +1,25 @@
+# Introduction
+
+Fresh out of college, you're throwing a huge party to celebrate with friends and family.
+Over 70 people have shown up, including your mildly eccentric Uncle Ted.
+
+In one of his usual antics, he bets you £100 that at least two people in the room share the same birthday.
+That sounds ridiculous — there are many more possible birthdays than there are guests, so you confidently accept.
+
+To your astonishment, after collecting the birthdays of just 32 guests, you've already found two guests that share the same birthday.
+Accepting your loss, you hand Uncle Ted his £100, but something feels off.
+
+The next day, curiosity gets the better of you.
+A quick web search leads you to the [birthday paradox][birthday-problem], which reveals that with just 23 people, the probability of a shared birthday exceeds 50%.
+
+Ah. So _that's_ why Uncle Ted was so confident.
+
+Determined to turn the tables, you start looking up other paradoxes; next time, _you'll_ be the one making the bets.
+
+~~~~exercism/note
+The birthday paradox is a [veridical paradox][veridical-paradox]: even though it feels wrong, it is actually true.
+
+[veridical-paradox]: https://en.wikipedia.org/wiki/Paradox#Quine's_classification
+~~~~
+
+[birthday-problem]: https://en.wikipedia.org/wiki/Birthday_problem
diff --git a/exercises/practice/baffling-birthdays/.meta/config.json b/exercises/practice/baffling-birthdays/.meta/config.json
new file mode 100644
index 000000000..6e401cb62
--- /dev/null
+++ b/exercises/practice/baffling-birthdays/.meta/config.json
@@ -0,0 +1,22 @@
+{
+  "authors": [
+    "Baboushka"
+  ],
+  "files": {
+    "solution": [
+      "src/main/java/BafflingBirthdays.java"
+    ],
+    "test": [
+      "src/test/java/BafflingBirthdaysTest.java"
+    ],
+    "example": [
+      ".meta/src/reference/java/BafflingBirthdays.java"
+    ],
+    "invalidator": [
+      "build.gradle"
+    ]
+  },
+  "blurb": "Estimate the birthday paradox's probabilities.",
+  "source": "Erik Schierboom",
+  "source_url": "https://github.com/exercism/problem-specifications/pull/2539"
+}
diff --git a/exercises/practice/baffling-birthdays/.meta/src/reference/java/BafflingBirthdays.java b/exercises/practice/baffling-birthdays/.meta/src/reference/java/BafflingBirthdays.java
new file mode 100644
index 000000000..03cf1ae9a
--- /dev/null
+++ b/exercises/practice/baffling-birthdays/.meta/src/reference/java/BafflingBirthdays.java
@@ -0,0 +1,50 @@
+import java.time.LocalDate;
+import java.util.ArrayList;
+import java.util.concurrent.ThreadLocalRandom;
+import java.util.HashSet;
+import java.util.List;
+import java.util.Set;
+
+class BafflingBirthdays {
+    private static final int nonLeapYear = 2001;
+    private static final int daysInYear = 365;
+
+    boolean sharedBirthday(List<String> birthdates) {
+        Set<String> seen = new HashSet<>();
+        for (String birthdate : birthdates) {
+            String monthDay = birthdate.substring(5);
+            if (!seen.add(monthDay)) {
+                return true;
+            }
+        }
+        return false;
+    }
+    
+    List<String> randomBirthdates(int groupSize) {
+        if (groupSize <= 0) {
+            return List.of();
+        }
+        List<String> birthdates = new ArrayList<>(groupSize);
+        ThreadLocalRandom random = ThreadLocalRandom.current();
+        for (int i = 0; i < groupSize; i++) {
+            int dayOfYear = random.nextInt(1, daysInYear + 1);
+            LocalDate date = LocalDate.ofYearDay(nonLeapYear, dayOfYear);
+            birthdates.add(date.toString());
+        }
+        return birthdates;
+    }
+
+    double estimatedProbabilityOfSharedBirthday(int groupSize) {
+        if (groupSize <= 1) {
+            return 0.0;
+        }
+        if (groupSize > daysInYear) {
+            return 100.0;
+        }
+        double probabilityNoSharedBirthday = 1.0;
+        for (int k = 0; k < groupSize; k++) {
+            probabilityNoSharedBirthday *= (daysInYear - k) / (double) daysInYear;
+        }
+        return (1 - probabilityNoSharedBirthday) * 100.0;
+    }
+}
diff --git a/exercises/practice/baffling-birthdays/.meta/tests.toml b/exercises/practice/baffling-birthdays/.meta/tests.toml
new file mode 100644
index 000000000..c76afb466
--- /dev/null
+++ b/exercises/practice/baffling-birthdays/.meta/tests.toml
@@ -0,0 +1,61 @@
+# This is an auto-generated file.
+#
+# Regenerating this file via `configlet sync` will:
+# - Recreate every `description` key/value pair
+# - Recreate every `reimplements` key/value pair, where they exist in problem-specifications
+# - Remove any `include = true` key/value pair (an omitted `include` key implies inclusion)
+# - Preserve any other key/value pair
+#
+# As user-added comments (using the # character) will be removed when this file
+# is regenerated, comments can be added via a `comment` key.
+
+[716dcc2b-8fe4-4fc9-8c48-cbe70d8e6b67]
+description = "shared birthday -> one birthdate"
+
+[f7b3eb26-bcfc-4c1e-a2de-af07afc33f45]
+description = "shared birthday -> two birthdates with same year, month, and day"
+
+[7193409a-6e16-4bcb-b4cc-9ffe55f79b25]
+description = "shared birthday -> two birthdates with same year and month, but different day"
+
+[d04db648-121b-4b72-93e8-d7d2dced4495]
+description = "shared birthday -> two birthdates with same month and day, but different year"
+
+[3c8bd0f0-14c6-4d4c-975a-4c636bfdc233]
+description = "shared birthday -> two birthdates with same year, but different month and day"
+
+[df5daba6-0879-4480-883c-e855c99cdaa3]
+description = "shared birthday -> two birthdates with different year, month, and day"
+
+[0c17b220-cbb9-4bd7-872f-373044c7b406]
+description = "shared birthday -> multiple birthdates without shared birthday"
+
+[966d6b0b-5c0a-4b8c-bc2d-64939ada49f8]
+description = "shared birthday -> multiple birthdates with one shared birthday"
+
+[b7937d28-403b-4500-acce-4d9fe3a9620d]
+description = "shared birthday -> multiple birthdates with more than one shared birthday"
+
+[70b38cea-d234-4697-b146-7d130cd4ee12]
+description = "random birthdates -> generate requested number of birthdates"
+
+[d9d5b7d3-5fea-4752-b9c1-3fcd176d1b03]
+description = "random birthdates -> years are not leap years"
+
+[d1074327-f68c-4c8a-b0ff-e3730d0f0521]
+description = "random birthdates -> months are random"
+
+[7df706b3-c3f5-471d-9563-23a4d0577940]
+description = "random birthdates -> days are random"
+
+[89a462a4-4265-4912-9506-fb027913f221]
+description = "estimated probability of at least one shared birthday -> for one person"
+
+[ec31c787-0ebb-4548-970c-5dcb4eadfb5f]
+description = "estimated probability of at least one shared birthday -> among ten people"
+
+[b548afac-a451-46a3-9bb0-cb1f60c48e2f]
+description = "estimated probability of at least one shared birthday -> among twenty-three people"
+
+[e43e6b9d-d77b-4f6c-a960-0fc0129a0bc5]
+description = "estimated probability of at least one shared birthday -> among seventy people"
diff --git a/exercises/practice/baffling-birthdays/build.gradle b/exercises/practice/baffling-birthdays/build.gradle
new file mode 100644
index 000000000..d28f35dee
--- /dev/null
+++ b/exercises/practice/baffling-birthdays/build.gradle
@@ -0,0 +1,25 @@
+plugins {
+    id "java"
+}
+
+repositories {
+    mavenCentral()
+}
+
+dependencies {
+    testImplementation platform("org.junit:junit-bom:5.10.0")
+    testImplementation "org.junit.jupiter:junit-jupiter"
+    testImplementation "org.assertj:assertj-core:3.25.1"
+
+    testRuntimeOnly "org.junit.platform:junit-platform-launcher"
+}
+
+test {
+    useJUnitPlatform()
+
+    testLogging {
+        exceptionFormat = "full"
+        showStandardStreams = true
+        events = ["passed", "failed", "skipped"]
+    }
+}
diff --git a/exercises/practice/baffling-birthdays/gradle/wrapper/gradle-wrapper.jar b/exercises/practice/baffling-birthdays/gradle/wrapper/gradle-wrapper.jar
new file mode 100644
index 000000000..f8e1ee312
Binary files /dev/null and b/exercises/practice/baffling-birthdays/gradle/wrapper/gradle-wrapper.jar differ
diff --git a/exercises/practice/baffling-birthdays/gradle/wrapper/gradle-wrapper.properties b/exercises/practice/baffling-birthdays/gradle/wrapper/gradle-wrapper.properties
new file mode 100644
index 000000000..4d97ea344
--- /dev/null
+++ b/exercises/practice/baffling-birthdays/gradle/wrapper/gradle-wrapper.properties
@@ -0,0 +1,6 @@
+distributionBase=GRADLE_USER_HOME
+distributionPath=wrapper/dists
+distributionUrl=https\://services.gradle.org/distributions/gradle-9.2.1-bin.zip
+validateDistributionUrl=true
+zipStoreBase=GRADLE_USER_HOME
+zipStorePath=wrapper/dists
diff --git a/exercises/practice/baffling-birthdays/gradlew b/exercises/practice/baffling-birthdays/gradlew
new file mode 100644
index 000000000..adff685a0
--- /dev/null
+++ b/exercises/practice/baffling-birthdays/gradlew
@@ -0,0 +1,248 @@
+#!/bin/sh
+
+#
+# Copyright © 2015 the original authors.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#      https://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+#
+# SPDX-License-Identifier: Apache-2.0
+#
+
+##############################################################################
+#
+#   Gradle start up script for POSIX generated by Gradle.
+#
+#   Important for running:
+#
+#   (1) You need a POSIX-compliant shell to run this script. If your /bin/sh is
+#       noncompliant, but you have some other compliant shell such as ksh or
+#       bash, then to run this script, type that shell name before the whole
+#       command line, like:
+#
+#           ksh Gradle
+#
+#       Busybox and similar reduced shells will NOT work, because this script
+#       requires all of these POSIX shell features:
+#         * functions;
+#         * expansions «$var», «${var}», «${var:-default}», «${var+SET}»,
+#           «${var#prefix}», «${var%suffix}», and «$( cmd )»;
+#         * compound commands having a testable exit status, especially «case»;
+#         * various built-in commands including «command», «set», and «ulimit».
+#
+#   Important for patching:
+#
+#   (2) This script targets any POSIX shell, so it avoids extensions provided
+#       by Bash, Ksh, etc; in particular arrays are avoided.
+#
+#       The "traditional" practice of packing multiple parameters into a
+#       space-separated string is a well documented source of bugs and security
+#       problems, so this is (mostly) avoided, by progressively accumulating
+#       options in "$@", and eventually passing that to Java.
+#
+#       Where the inherited environment variables (DEFAULT_JVM_OPTS, JAVA_OPTS,
+#       and GRADLE_OPTS) rely on word-splitting, this is performed explicitly;
+#       see the in-line comments for details.
+#
+#       There are tweaks for specific operating systems such as AIX, CygWin,
+#       Darwin, MinGW, and NonStop.
+#
+#   (3) This script is generated from the Groovy template
+#       https://github.com/gradle/gradle/blob/HEAD/platforms/jvm/plugins-application/src/main/resources/org/gradle/api/internal/plugins/unixStartScript.txt
+#       within the Gradle project.
+#
+#       You can find Gradle at https://github.com/gradle/gradle/.
+#
+##############################################################################
+
+# Attempt to set APP_HOME
+
+# Resolve links: $0 may be a link
+app_path=$0
+
+# Need this for daisy-chained symlinks.
+while
+    APP_HOME=${app_path%"${app_path##*/}"}  # leaves a trailing /; empty if no leading path
+    [ -h "$app_path" ]
+do
+    ls=$( ls -ld "$app_path" )
+    link=${ls#*' -> '}
+    case $link in             #(
+      /*)   app_path=$link ;; #(
+      *)    app_path=$APP_HOME$link ;;
+    esac
+done
+
+# This is normally unused
+# shellcheck disable=SC2034
+APP_BASE_NAME=${0##*/}
+# Discard cd standard output in case $CDPATH is set (https://github.com/gradle/gradle/issues/25036)
+APP_HOME=$( cd -P "${APP_HOME:-./}" > /dev/null && printf '%s\n' "$PWD" ) || exit
+
+# Use the maximum available, or set MAX_FD != -1 to use that value.
+MAX_FD=maximum
+
+warn () {
+    echo "$*"
+} >&2
+
+die () {
+    echo
+    echo "$*"
+    echo
+    exit 1
+} >&2
+
+# OS specific support (must be 'true' or 'false').
+cygwin=false
+msys=false
+darwin=false
+nonstop=false
+case "$( uname )" in                #(
+  CYGWIN* )         cygwin=true  ;; #(
+  Darwin* )         darwin=true  ;; #(
+  MSYS* | MINGW* )  msys=true    ;; #(
+  NONSTOP* )        nonstop=true ;;
+esac
+
+
+
+# Determine the Java command to use to start the JVM.
+if [ -n "$JAVA_HOME" ] ; then
+    if [ -x "$JAVA_HOME/jre/sh/java" ] ; then
+        # IBM's JDK on AIX uses strange locations for the executables
+        JAVACMD=$JAVA_HOME/jre/sh/java
+    else
+        JAVACMD=$JAVA_HOME/bin/java
+    fi
+    if [ ! -x "$JAVACMD" ] ; then
+        die "ERROR: JAVA_HOME is set to an invalid directory: $JAVA_HOME
+
+Please set the JAVA_HOME variable in your environment to match the
+location of your Java installation."
+    fi
+else
+    JAVACMD=java
+    if ! command -v java >/dev/null 2>&1
+    then
+        die "ERROR: JAVA_HOME is not set and no 'java' command could be found in your PATH.
+
+Please set the JAVA_HOME variable in your environment to match the
+location of your Java installation."
+    fi
+fi
+
+# Increase the maximum file descriptors if we can.
+if ! "$cygwin" && ! "$darwin" && ! "$nonstop" ; then
+    case $MAX_FD in #(
+      max*)
+        # In POSIX sh, ulimit -H is undefined. That's why the result is checked to see if it worked.
+        # shellcheck disable=SC2039,SC3045
+        MAX_FD=$( ulimit -H -n ) ||
+            warn "Could not query maximum file descriptor limit"
+    esac
+    case $MAX_FD in  #(
+      '' | soft) :;; #(
+      *)
+        # In POSIX sh, ulimit -n is undefined. That's why the result is checked to see if it worked.
+        # shellcheck disable=SC2039,SC3045
+        ulimit -n "$MAX_FD" ||
+            warn "Could not set maximum file descriptor limit to $MAX_FD"
+    esac
+fi
+
+# Collect all arguments for the java command, stacking in reverse order:
+#   * args from the command line
+#   * the main class name
+#   * -classpath
+#   * -D...appname settings
+#   * --module-path (only if needed)
+#   * DEFAULT_JVM_OPTS, JAVA_OPTS, and GRADLE_OPTS environment variables.
+
+# For Cygwin or MSYS, switch paths to Windows format before running java
+if "$cygwin" || "$msys" ; then
+    APP_HOME=$( cygpath --path --mixed "$APP_HOME" )
+
+    JAVACMD=$( cygpath --unix "$JAVACMD" )
+
+    # Now convert the arguments - kludge to limit ourselves to /bin/sh
+    for arg do
+        if
+            case $arg in                                #(
+              -*)   false ;;                            # don't mess with options #(
+              /?*)  t=${arg#/} t=/${t%%/*}              # looks like a POSIX filepath
+                    [ -e "$t" ] ;;                      #(
+              *)    false ;;
+            esac
+        then
+            arg=$( cygpath --path --ignore --mixed "$arg" )
+        fi
+        # Roll the args list around exactly as many times as the number of
+        # args, so each arg winds up back in the position where it started, but
+        # possibly modified.
+        #
+        # NB: a `for` loop captures its iteration list before it begins, so
+        # changing the positional parameters here affects neither the number of
+        # iterations, nor the values presented in `arg`.
+        shift                   # remove old arg
+        set -- "$@" "$arg"      # push replacement arg
+    done
+fi
+
+
+# Add default JVM options here. You can also use JAVA_OPTS and GRADLE_OPTS to pass JVM options to this script.
+DEFAULT_JVM_OPTS='"-Xmx64m" "-Xms64m"'
+
+# Collect all arguments for the java command:
+#   * DEFAULT_JVM_OPTS, JAVA_OPTS, and optsEnvironmentVar are not allowed to contain shell fragments,
+#     and any embedded shellness will be escaped.
+#   * For example: A user cannot expect ${Hostname} to be expanded, as it is an environment variable and will be
+#     treated as '${Hostname}' itself on the command line.
+
+set -- \
+        "-Dorg.gradle.appname=$APP_BASE_NAME" \
+        -jar "$APP_HOME/gradle/wrapper/gradle-wrapper.jar" \
+        "$@"
+
+# Stop when "xargs" is not available.
+if ! command -v xargs >/dev/null 2>&1
+then
+    die "xargs is not available"
+fi
+
+# Use "xargs" to parse quoted args.
+#
+# With -n1 it outputs one arg per line, with the quotes and backslashes removed.
+#
+# In Bash we could simply go:
+#
+#   readarray ARGS < <( xargs -n1 <<<"$var" ) &&
+#   set -- "${ARGS[@]}" "$@"
+#
+# but POSIX shell has neither arrays nor command substitution, so instead we
+# post-process each arg (as a line of input to sed) to backslash-escape any
+# character that might be a shell metacharacter, then use eval to reverse
+# that process (while maintaining the separation between arguments), and wrap
+# the whole thing up as a single "set" statement.
+#
+# This will of course break if any of these variables contains a newline or
+# an unmatched quote.
+#
+
+eval "set -- $(
+        printf '%s\n' "$DEFAULT_JVM_OPTS $JAVA_OPTS $GRADLE_OPTS" |
+        xargs -n1 |
+        sed ' s~[^-[:alnum:]+,./:=@_]~\\&~g; ' |
+        tr '\n' ' '
+    )" '"$@"'
+
+exec "$JAVACMD" "$@"
diff --git a/exercises/practice/baffling-birthdays/gradlew.bat b/exercises/practice/baffling-birthdays/gradlew.bat
new file mode 100644
index 000000000..c4bdd3ab8
--- /dev/null
+++ b/exercises/practice/baffling-birthdays/gradlew.bat
@@ -0,0 +1,93 @@
+@rem
+@rem Copyright 2015 the original author or authors.
+@rem
+@rem Licensed under the Apache License, Version 2.0 (the "License");
+@rem you may not use this file except in compliance with the License.
+@rem You may obtain a copy of the License at
+@rem
+@rem      https://www.apache.org/licenses/LICENSE-2.0
+@rem
+@rem Unless required by applicable law or agreed to in writing, software
+@rem distributed under the License is distributed on an "AS IS" BASIS,
+@rem WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+@rem See the License for the specific language governing permissions and
+@rem limitations under the License.
+@rem
+@rem SPDX-License-Identifier: Apache-2.0
+@rem
+
+@if "%DEBUG%"=="" @echo off
+@rem ##########################################################################
+@rem
+@rem  Gradle startup script for Windows
+@rem
+@rem ##########################################################################
+
+@rem Set local scope for the variables with windows NT shell
+if "%OS%"=="Windows_NT" setlocal
+
+set DIRNAME=%~dp0
+if "%DIRNAME%"=="" set DIRNAME=.
+@rem This is normally unused
+set APP_BASE_NAME=%~n0
+set APP_HOME=%DIRNAME%
+
+@rem Resolve any "." and ".." in APP_HOME to make it shorter.
+for %%i in ("%APP_HOME%") do set APP_HOME=%%~fi
+
+@rem Add default JVM options here. You can also use JAVA_OPTS and GRADLE_OPTS to pass JVM options to this script.
+set DEFAULT_JVM_OPTS="-Xmx64m" "-Xms64m"
+
+@rem Find java.exe
+if defined JAVA_HOME goto findJavaFromJavaHome
+
+set JAVA_EXE=java.exe
+%JAVA_EXE% -version >NUL 2>&1
+if %ERRORLEVEL% equ 0 goto execute
+
+echo. 1>&2
+echo ERROR: JAVA_HOME is not set and no 'java' command could be found in your PATH. 1>&2
+echo. 1>&2
+echo Please set the JAVA_HOME variable in your environment to match the 1>&2
+echo location of your Java installation. 1>&2
+
+goto fail
+
+:findJavaFromJavaHome
+set JAVA_HOME=%JAVA_HOME:"=%
+set JAVA_EXE=%JAVA_HOME%/bin/java.exe
+
+if exist "%JAVA_EXE%" goto execute
+
+echo. 1>&2
+echo ERROR: JAVA_HOME is set to an invalid directory: %JAVA_HOME% 1>&2
+echo. 1>&2
+echo Please set the JAVA_HOME variable in your environment to match the 1>&2
+echo location of your Java installation. 1>&2
+
+goto fail
+
+:execute
+@rem Setup the command line
+
+
+
+@rem Execute Gradle
+"%JAVA_EXE%" %DEFAULT_JVM_OPTS% %JAVA_OPTS% %GRADLE_OPTS% "-Dorg.gradle.appname=%APP_BASE_NAME%" -jar "%APP_HOME%\gradle\wrapper\gradle-wrapper.jar" %*
+
+:end
+@rem End local scope for the variables with windows NT shell
+if %ERRORLEVEL% equ 0 goto mainEnd
+
+:fail
+rem Set variable GRADLE_EXIT_CONSOLE if you need the _script_ return code instead of
+rem the _cmd.exe /c_ return code!
+set EXIT_CODE=%ERRORLEVEL%
+if %EXIT_CODE% equ 0 set EXIT_CODE=1
+if not ""=="%GRADLE_EXIT_CONSOLE%" exit %EXIT_CODE%
+exit /b %EXIT_CODE%
+
+:mainEnd
+if "%OS%"=="Windows_NT" endlocal
+
+:omega
diff --git a/exercises/practice/baffling-birthdays/src/main/java/BafflingBirthdays.java b/exercises/practice/baffling-birthdays/src/main/java/BafflingBirthdays.java
new file mode 100644
index 000000000..273c6506c
--- /dev/null
+++ b/exercises/practice/baffling-birthdays/src/main/java/BafflingBirthdays.java
@@ -0,0 +1,15 @@
+import java.util.List;
+
+class BafflingBirthdays {
+    boolean sharedBirthday(List<String> birthdates) {
+        throw new UnsupportedOperationException("Delete this statement and write your own implementation.");
+    }
+
+    List<String> randomBirthdates(int groupSize) {
+        throw new UnsupportedOperationException("Delete this statement and write your own implementation.");
+    }
+
+    double estimatedProbabilityOfSharedBirthday(int groupSize) {
+        throw new UnsupportedOperationException("Delete this statement and write your own implementation.");
+    }
+}
\ No newline at end of file
diff --git a/exercises/practice/baffling-birthdays/src/test/java/BafflingBirthdaysTest.java b/exercises/practice/baffling-birthdays/src/test/java/BafflingBirthdaysTest.java
new file mode 100644
index 000000000..9c9497a92
--- /dev/null
+++ b/exercises/practice/baffling-birthdays/src/test/java/BafflingBirthdaysTest.java
@@ -0,0 +1,160 @@
+import org.junit.jupiter.api.Disabled;
+import org.junit.jupiter.api.DisplayName;
+import org.junit.jupiter.api.Test;
+
+import static org.assertj.core.api.Assertions.assertThat;
+import static org.assertj.core.data.Offset.offset;
+
+import java.time.LocalDate;
+import java.util.HashSet;
+import java.util.List;
+import java.util.Set;
+
+public class BafflingBirthdaysTest {
+    private BafflingBirthdays birthdays = new BafflingBirthdays();
+
+    @Test
+    @DisplayName("one birthdate")
+    public void oneBirthdateTest() {
+        assertThat(birthdays.sharedBirthday(List.of("2000-01-01"))).isFalse();
+    }
+
+    @Disabled("Remove to run test")
+    @Test
+    @DisplayName("two birthdates with same year, month, and day")
+    public void twoBirthdatesWithSameYearMonthAndDayTest() {
+        assertThat(birthdays.sharedBirthday(List.of("2000-01-01", "2000-01-01"))).isTrue();
+    }
+
+    @Disabled("Remove to run test")
+    @Test
+    @DisplayName("two birthdates with same year and month, but different day")
+    public void twoBirthdatesWithSameYearAndMonthButDifferentDayTest() {
+        assertThat(birthdays.sharedBirthday(List.of("2012-05-09", "2012-05-17"))).isFalse();
+    }
+
+    @Disabled("Remove to run test")
+    @Test
+    @DisplayName("two birthdates with same month and day, but different year")
+    public void twoBirthdatesWithSameMonthAndDayButDifferentYearTest() {
+        assertThat(birthdays.sharedBirthday(List.of("1999-10-23", "1988-10-23"))).isTrue();
+    }
+
+    @Disabled("Remove to run test")
+    @Test
+    @DisplayName("two birthdates with same year, but different month and day")
+    public void twoBirthdatesWithSameYearButDifferentMonthAndDayTest() {
+        assertThat(birthdays.sharedBirthday(List.of("2007-12-19", "2007-04-27"))).isFalse();
+    }
+
+    @Disabled("Remove to run test")
+    @Test
+    @DisplayName("two birthdates with different year, month, and day")
+    public void twoBirthdatesWithDifferentYearMonthAndDayTest() {
+        assertThat(birthdays.sharedBirthday(List.of("1997-08-04", "1963-11-23"))).isFalse();
+    }
+
+    @Disabled("Remove to run test")
+    @Test
+    @DisplayName("multiple birthdates without shared birthday")
+    public void multipleBirthdatesWithoutSharedBirthdayTest() {
+        assertThat(birthdays.sharedBirthday(List.of("1966-07-29", "1977-02-12", "2001-12-25", "1980-11-10"))).isFalse();
+    }
+
+    @Disabled("Remove to run test")
+    @Test
+    @DisplayName("multiple birthdates with one shared birthday")
+    public void multipleBirthdatesWithOneSharedBirthdayTest() {
+        assertThat(birthdays.sharedBirthday(List.of("1966-07-29", "1977-02-12", "2001-07-29", "1980-11-10"))).isTrue();
+    }
+
+    @Disabled("Remove to run test")
+    @Test
+    @DisplayName("multiple birthdates with more than one shared birthday")
+    public void multipleBirthdatesWithMoreThanOneSharedBirthdayTest() {
+        assertThat(birthdays.sharedBirthday(List.of(
+                "1966-07-29",
+                "1977-02-12",
+                "2001-12-25",
+                "1980-07-29",
+                "2019-02-12"
+        ))).isTrue();
+    }
+
+    @Disabled("Remove to run test")
+    @Test
+    @DisplayName("generate requested number of birthdates")
+    public void generateRequestedNumberOfBirthdatesTest() {
+        int groupSize = 50;
+        assertThat(birthdays.randomBirthdates(groupSize).size()).isEqualTo(groupSize);
+    }
+
+    @Disabled("Remove to run test")
+    @Test
+    @DisplayName("years are not leap years")
+    public void yearsAreNotLeapYearsTest() {
+        for (String birthdate : birthdays.randomBirthdates(100)) {
+            LocalDate date = LocalDate.parse(birthdate);
+            assertThat(date.isLeapYear()).isFalse();
+            assertThat(date.getMonthValue() == 2 && date.getDayOfMonth() == 29).isFalse();
+        }
+    }
+
+    @Disabled("Remove to run test")
+    @Test
+    @DisplayName("months are random")
+    public void monthsAreRandomTest() {
+        Set<Integer> months = new HashSet<>();
+        for (String birthdate : birthdays.randomBirthdates(500)) {
+            LocalDate date = LocalDate.parse(birthdate);
+            months.add(date.getMonthValue());
+            if (months.size() >= 7) {
+                break;
+            }
+        }
+        assertThat(months).hasSizeGreaterThanOrEqualTo(7);
+    }
+
+    @Disabled("Remove to run test")
+    @Test
+    @DisplayName("days are random")
+    public void daysAreRandomTest() {
+        Set<Integer> days = new HashSet<>();
+        for (String birthdate : birthdays.randomBirthdates(500)) {
+            LocalDate date = LocalDate.parse(birthdate);
+            days.add(date.getDayOfMonth());
+            if (days.size() >= 11) {
+                break;
+            }
+        }
+        assertThat(days).hasSizeGreaterThanOrEqualTo(11);
+    }
+
+    @Disabled("Remove to run test")
+    @Test
+    @DisplayName("estimated probability of at least one shared birthday case for one person")
+    public void estimatedProbabilityOfAtLeastOneSharedBirthdayForOnePersonTest() {
+        assertThat(birthdays.estimatedProbabilityOfSharedBirthday(1)).isEqualTo(0.0);
+    }
+
+    @Disabled("Remove to run test")
+    @Test
+    @DisplayName("estimated probability of at least one shared birthday case among ten people")
+    public void estimatedProbabilityOfAtLeastOneSharedBirthdayAmongTenPeopleTest() {
+        assertThat(birthdays.estimatedProbabilityOfSharedBirthday(10)).isCloseTo(11.694818, offset(1.0));
+    }
+
+    @Disabled("Remove to run test")
+    @Test
+    @DisplayName("estimated probability of at least one shared birthday case among twenty-three people")
+    public void estimatedProbabilityOfAtLeastOneSharedBirthdayAmongTwentyThreePeopleTest() {
+        assertThat(birthdays.estimatedProbabilityOfSharedBirthday(23)).isCloseTo(50.729723, offset(1.0));
+    }
+
+    @Disabled("Remove to run test")
+    @Test
+    @DisplayName("estimated probability of at least one shared birthday case among seventy people")
+    public void estimatedProbabilityOfAtLeastOneSharedBirthdayAmongSeventyPeopleTest() {
+        assertThat(birthdays.estimatedProbabilityOfSharedBirthday(70)).isCloseTo(99.915958, offset(1.0));
+    }
+}
diff --git a/exercises/settings.gradle b/exercises/settings.gradle
index 1119f4b98..6bf710357 100644
--- a/exercises/settings.gradle
+++ b/exercises/settings.gradle
@@ -40,6 +40,7 @@ include 'practice:bank-account'
 // include 'practice:binary' // deprecated
 include 'practice:binary-search'
 include 'practice:binary-search-tree'
+include 'practice:baffling-birthdays'
 include 'practice:bob'
 include 'practice:book-store'
 include 'practice:bottle-song'