diff --git a/P/Sd1/Timeperiod/.gitignore b/P/Sd1/Timeperiod/.gitignore
new file mode 100644
index 0000000000000000000000000000000000000000..2275479e375a621edeb852701cba9ea53b67ee7e
--- /dev/null
+++ b/P/Sd1/Timeperiod/.gitignore
@@ -0,0 +1,56 @@
+/target/
+/.settings/
+.classpath
+.project
+dependency-reduced-pom.xml
+*.log
+
+# Covers JetBrains IDEs: IntelliJ, RubyMine, PhpStorm, AppCode, PyCharm, CLion, Android Studio and Webstorm
+# Reference: https://intellij-support.jetbrains.com/hc/en-us/articles/206544839
+
+# User-specific stuff:
+.idea/**/workspace.xml
+.idea/**/tasks.xml
+.idea/dictionaries
+
+# Sensitive or high-churn files:
+.idea/**/dataSources/
+.idea/**/dataSources.ids
+.idea/**/dataSources.xml
+.idea/**/dataSources.local.xml
+.idea/**/sqlDataSources.xml
+.idea/**/dynamic.xml
+.idea/**/uiDesigner.xml
+
+# Gradle:
+.idea/**/gradle.xml
+.idea/**/libraries
+
+# CMake
+cmake-build-debug/
+
+# Mongo Explorer plugin:
+.idea/**/mongoSettings.xml
+
+## File-based project format:
+*.iws
+
+## Plugin-specific files:
+
+# IntelliJ
+out/
+
+# mpeltonen/sbt-idea plugin
+.idea_modules/
+
+# JIRA plugin
+atlassian-ide-plugin.xml
+
+# Cursive Clojure plugin
+.idea/replstate.xml
+
+# Crashlytics plugin (for Android Studio and IntelliJ)
+com_crashlytics_export_strings.xml
+crashlytics.properties
+crashlytics-build.properties
+fabric.properties
diff --git a/P/Sd1/Timeperiod/pom.xml b/P/Sd1/Timeperiod/pom.xml
new file mode 100644
index 0000000000000000000000000000000000000000..82d2709c6932cf400b039b6d2a0731d1dc107e16
--- /dev/null
+++ b/P/Sd1/Timeperiod/pom.xml
@@ -0,0 +1,82 @@
+<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+ xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
+ <modelVersion>4.0.0</modelVersion>
+
+ <groupId>de.hdm_stuttgart.mi.sd1</groupId>
+ <artifactId>timeperiod</artifactId>
+ <version>0.9</version>
+ <packaging>jar</packaging>
+
+ <name>timeperiod</name>
+
+ <url>https://freedocs.mi.hdm-stuttgart.de/sd1SectToolsOfTheTrade2.html</url>
+
+ <description>Basic Java project providing Junit 4 testing and log4j2 logging.</description>
+
+ <properties>
+ <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
+ </properties>
+
+ <dependencies>
+ <dependency>
+ <groupId>junit</groupId>
+ <artifactId>junit</artifactId>
+ <version>4.12</version>
+ <scope>test</scope>
+ </dependency>
+
+ <dependency>
+ <groupId>org.apache.logging.log4j</groupId>
+ <artifactId>log4j-core</artifactId>
+ <version>2.11.0</version>
+ </dependency>
+
+ </dependencies>
+
+ <build>
+ <plugins>
+
+ <plugin>
+ <groupId>org.apache.maven.plugins</groupId>
+ <artifactId>maven-compiler-plugin</artifactId>
+ <version>3.7.0</version>
+ <configuration>
+ <source>1.8</source>
+ <target>1.8</target>
+ </configuration>
+ </plugin>
+
+ <plugin>
+ <groupId>org.apache.maven.plugins</groupId>
+ <artifactId>maven-javadoc-plugin</artifactId>
+ <version>3.0.0</version>
+ <configuration/>
+ </plugin>
+
+ <plugin>
+ <groupId>org.apache.maven.plugins</groupId>
+ <artifactId>maven-shade-plugin</artifactId>
+ <version>3.1.0</version>
+ <configuration>
+ <transformers>
+ <transformer
+ implementation="org.apache.maven.plugins.shade.resource.ManifestResourceTransformer">
+ <manifestEntries>
+ <Main-Class>de.hdm_stuttgart.mi.sd1.App</Main-Class>
+ </manifestEntries>
+ </transformer>
+ </transformers>
+ </configuration>
+ <executions>
+ <execution>
+ <phase>package</phase>
+ <goals>
+ <goal>shade</goal>
+ </goals>
+ </execution>
+ </executions>
+ </plugin>
+
+ </plugins>
+ </build>
+</project>
\ No newline at end of file
diff --git a/P/Sd1/Timeperiod/src/main/java/de/hdm_stuttgart/mi/sd1/App.java b/P/Sd1/Timeperiod/src/main/java/de/hdm_stuttgart/mi/sd1/App.java
new file mode 100644
index 0000000000000000000000000000000000000000..1138b122c97fca1bffc0d9384c277b5365fce423
--- /dev/null
+++ b/P/Sd1/Timeperiod/src/main/java/de/hdm_stuttgart/mi/sd1/App.java
@@ -0,0 +1,31 @@
+package de.hdm_stuttgart.mi.sd1;
+
+/**
+ * A demo using {@link Timeperiod} instances.
+ */
+
+public class App {
+ /**
+ * Main entry point.
+ *
+ * @param args Yet unused
+ */
+ public static void main(String[] args) {
+ test1();
+ test2();
+ }
+
+
+ static private void test1() {
+ final Timeperiod t = new Timeperiod(112223);
+ System.out.println(92 + " seconds are equal to " + t);
+ }
+ static private void test2() {
+ final Timeperiod t = new Timeperiod(2310983);
+ System.out.print("weeks = " + t.weeks +
+ "\ndays=" + t.days +
+ "\nhours=" + t.hours +
+ "\nminutes=" + t.minutes +
+ "\nseconds=" + t.seconds + "\n");
+ }
+}
\ No newline at end of file
diff --git a/P/Sd1/Timeperiod/src/main/java/de/hdm_stuttgart/mi/sd1/Timeperiod.java b/P/Sd1/Timeperiod/src/main/java/de/hdm_stuttgart/mi/sd1/Timeperiod.java
new file mode 100644
index 0000000000000000000000000000000000000000..47af9c58a8c7d07b2c555feaa1b89d169fa9e017
--- /dev/null
+++ b/P/Sd1/Timeperiod/src/main/java/de/hdm_stuttgart/mi/sd1/Timeperiod.java
@@ -0,0 +1,133 @@
+package de.hdm_stuttgart.mi.sd1;
+
+/**
+ * <p>Representing time periods measured in seconds by decomposing them into
+ * seconds, minutes hours, days and weeks. See {@link #Timeperiod(int)}
+ * for details.</p>
+ */
+public class Timeperiod {
+
+ // Pre-caculated internal values
+ static private final int
+ SECONDS_PER_MINUTE = 60, // 60 minutes per hour
+ SECONDS_PER_HOUR = 60 * SECONDS_PER_MINUTE, // 3600 seconds per hour
+ SECONDS_PER_DAY = 24 * SECONDS_PER_HOUR, // 86400 seconds per day
+ SECONDS_PER_WEEK = 7 * SECONDS_PER_DAY; // 604800 seconds per week
+
+ // Tedious calculation, will happen only on-demand
+ private String toStringValue = null;
+
+ private String toStringImplement() {
+ final int highestValue;
+
+ if (0 < weeks) {
+ highestValue = 5; // weeks, days, hours, minutes and seconds
+ } else if (0 < days) {
+ highestValue = 4; // days, hours, minutes and seconds
+ } else if (0 < hours) {
+ highestValue = 3; // hours, minutes and seconds
+ } else if (0 < minutes) {
+ highestValue = 2; // minutes and seconds
+ } else {
+ highestValue = 1; // only seconds, potentially zero as well
+ }
+
+ final StringBuffer buffer = new StringBuffer();
+ switch (highestValue) {
+ case 5: addSingularOrPlural(buffer, weeks, "week", ", ");
+ case 4: addSingularOrPlural(buffer, days, "day", ", ");
+ case 3: addSingularOrPlural(buffer, hours, "hour", ", ");
+ case 2: addSingularOrPlural(buffer, minutes, "minute", ", ");
+ case 1: addSingularOrPlural(buffer, seconds, "second", " and ");
+ }
+ return buffer.toString();
+ }
+
+ static private void addSingularOrPlural(final StringBuffer results, final int count,
+ final String base, String separator) {
+
+ if (0 < results.toString().length()) { // Result buffer not empty? Separator required.
+ results.append(separator);
+ }
+ results.append(count).append(" ").append(base);
+ if (1 != count) {
+ results.append("s"); // 0 or plural, e.g. "3 seconds"
+ }
+ }
+
+ /**
+ * <p>Turning a given number of seconds into weeks, days, hours, minutes and seconds.
+ * * Example: 3729781 seconds are equivalent to the sum of 1 second, 3 minutes, 4 hours,
+ * * 1 day and 6 weeks.</p>
+ *
+ * @param seconds A time period provided in seconds.
+ */
+ public Timeperiod(int seconds) {
+
+ weeks = seconds / SECONDS_PER_WEEK;
+ seconds = seconds % SECONDS_PER_WEEK; // remaining seconds without weeks
+
+ days = seconds / SECONDS_PER_DAY;
+ seconds %= SECONDS_PER_DAY; // remaining seconds without days
+
+ hours = seconds / SECONDS_PER_HOUR;
+ seconds %= SECONDS_PER_HOUR; // remaining seconds without minutes
+
+ minutes = seconds / SECONDS_PER_MINUTE;
+ this.seconds = seconds % SECONDS_PER_MINUTE; // remaining seconds
+ }
+
+ /**
+ * Copy a given instance.
+ *
+ * @param timeperiod Instance to be cloned.
+ */
+ public Timeperiod(final Timeperiod timeperiod) {
+ seconds = timeperiod.seconds;
+ minutes = timeperiod.minutes;
+ hours = timeperiod.hours;
+ days = timeperiod.days;
+ weeks = timeperiod.weeks;
+ toStringValue = timeperiod.toStringValue;
+ }
+
+ /**
+ * <p>providing a human readable form. The output corresponding to e.g. 112223 seconds will read:</p>
+ *
+ * <pre>1 day, 7 hours, 10 minutes and 23 seconds</pre>
+ *
+ * <p>Notice the absence of a "0 weeks" clause: Output starts with the »highest« non-zero component.</p>
+ *
+ * @return Informal description e.g. "1 day, 7 hours, 10 minutes and 23 seconds".
+ */
+ @Override
+ public String toString() {
+ // Value calculation is tedious, thus doing it only on-demand.
+ //
+ if (null == toStringValue) { // Called for the first time, yet uninitialized?
+ toStringValue = toStringImplement();
+ }
+ return toStringValue;
+ }
+
+ /**
+ * Time period's seconds portion.
+ */
+ public final int seconds;
+ /**
+ * Time period's minutes portion.
+ */
+ public final int minutes;
+ /**
+ * Time period's hours portion.
+ */
+ public final int hours;
+ /**
+ * Time period's days portion.
+ */
+ public final int days;
+ /**
+ * Time period's weeksportion.
+ */
+ public final int weeks;
+}
\ No newline at end of file
diff --git a/P/Sd1/Timeperiod/src/main/resources/log4j2.xml b/P/Sd1/Timeperiod/src/main/resources/log4j2.xml
new file mode 100644
index 0000000000000000000000000000000000000000..130f87a144c4eb0107a846e580c8fa7f5e819fc1
--- /dev/null
+++ b/P/Sd1/Timeperiod/src/main/resources/log4j2.xml
@@ -0,0 +1,21 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<Configuration>
+ <Appenders>
+ <File name="A1" fileName="A1.log" append="false">
+ <PatternLayout pattern="%t %-5p %c{2} - %m%n"/>
+ </File>
+ <Console name="STDOUT" target="SYSTEM_OUT">
+ <PatternLayout pattern="%d %-5p [%t] %C{2} (%F:%L) - %m%n"/>
+ </Console>
+ </Appenders>
+ <Loggers>
+
+ <!-- You my want to define class or package level per-logger rules -->
+ <Logger name="de.hdm_stuttgart.mi.sd1.App" level="debug">
+ <AppenderRef ref="A1"/>
+ </Logger>
+ <Root level="info">
+ <AppenderRef ref="STDOUT"/>
+ </Root>
+ </Loggers>
+</Configuration>
\ No newline at end of file
diff --git a/P/Sd1/Timeperiod/src/test/java/de/hdm_stuttgart/mi/sd1/TimeperiodTest.java b/P/Sd1/Timeperiod/src/test/java/de/hdm_stuttgart/mi/sd1/TimeperiodTest.java
new file mode 100644
index 0000000000000000000000000000000000000000..719507b17b42bb22542554183145923b69f9adb5
--- /dev/null
+++ b/P/Sd1/Timeperiod/src/test/java/de/hdm_stuttgart/mi/sd1/TimeperiodTest.java
@@ -0,0 +1,98 @@
+package de.hdm_stuttgart.mi.sd1;
+
+import org.junit.Assert;
+import org.junit.Test;
+
+/**
+ * Unit test of {@link Timeperiod}.
+ */
+public class TimeperiodTest {
+
+ // Helper methods for real tests.
+ static private void assertPeriodEqualImplement(final int expectedSeconds,
+ final int expectedMinutes,
+ final int expectedHours,
+ final int expectedDays,
+ final int expectedWeeks,
+ final String expectedToString,
+ final Timeperiod period) {
+ Assert.assertEquals(expectedSeconds, period.seconds);
+ Assert.assertEquals(expectedMinutes, period.minutes);
+ Assert.assertEquals(expectedHours, period.hours);
+ Assert.assertEquals(expectedDays, period.days);
+ Assert.assertEquals(expectedWeeks, period.weeks);
+
+ Assert.assertEquals(expectedToString, period.toString());
+
+ }
+
+ static private void assertPeriodEqual(final int expectedSeconds,
+ final int expectedMinutes,
+ final int expectedHours,
+ final int expectedDays,
+ final int expectedWeeks,
+ final String expectedToString,
+ final Timeperiod period) {
+
+ // Testing period in question
+ assertPeriodEqualImplement(
+ expectedSeconds, expectedMinutes, expectedHours, expectedDays, expectedWeeks, expectedToString,
+ period);
+
+ // Also testing copy constructor
+ assertPeriodEqualImplement(
+ expectedSeconds, expectedMinutes, expectedHours, expectedDays, expectedWeeks, expectedToString,
+ new Timeperiod(period));
+ }
+
+ /**
+ * Test constructor zero seconds.
+ */
+ @Test
+ public void testZero() {
+ assertPeriodEqual(
+ 0,0,0,0,0,
+ "0 seconds",
+ new Timeperiod(0));
+ }
+
+ @Test
+ public void testMinute() {
+ assertPeriodEqual(0,1,0,0,0,
+ "1 minute and 0 seconds",
+ new Timeperiod(60));
+ assertPeriodEqual(50,0,0,0,0,
+ "50 seconds",
+ new Timeperiod(50));
+ assertPeriodEqual(12,1,0,0,0,
+ "1 minute and 12 seconds",
+ new Timeperiod(72));
+ assertPeriodEqual(2,5,0,0,0,
+ "5 minutes and 2 seconds",
+ new Timeperiod(302));
+ }
+
+ @Test
+ public void testHour() {
+ assertPeriodEqual(0,0,2,0,0,
+ "2 hours, 0 minutes and 0 seconds",
+ new Timeperiod(7200));
+ assertPeriodEqual(59,59,0,0,0,
+ "59 minutes and 59 seconds",
+ new Timeperiod(3599));
+ assertPeriodEqual(40,1,1,0,0,
+ "1 hour, 1 minute and 40 seconds",
+ new Timeperiod(3700));
+ }
+
+ @Test
+ public void testVarious() {
+ assertPeriodEqual(1,3,4,1,6,
+ "6 weeks, 1 day, 4 hours, 3 minutes and 1 second",
+ new Timeperiod(3729781));
+
+ assertPeriodEqual(23,56,17,5,3,
+ "3 weeks, 5 days, 17 hours, 56 minutes and 23 seconds",
+ new Timeperiod(2310983));
+ }
+}
\ No newline at end of file