Tried to clean it up but it's still pretty dirty

src/main/java/io/zipcoder/MilitaryTime.java

@@ -0,0 +1,105 @@
+package io.zipcoder;
+
+import java.text.SimpleDateFormat;
+import java.util.Date;
+
+public class MilitaryTime {
+
+    private static String[] timeWords = {
+            "Zero",
+            "One",
+            "Two",
+            "Three",
+            "Four",
+            "Five",
+            "Six",
+            "Seven",
+            "Eight",
+            "Nine",
+            "Ten",
+            "Eleven",
+            "Twelve",
+            "Thirteen",
+            "Fourteen",
+            "Fifteen",
+            "Sixteen",
+            "Seventeen",
+            "Eighteen",
+            "Nineteen",
+    };
+
+    private static String[] tensWords = {
+            "Twenty",
+            "Thirty",
+            "Forty",
+            "Fifty"
+    };
+
+    public String convertToMilitaryTime(String time) throws Exception{
+        time = convertNumerically(time);
+        String[] splitTime = time.split(":");
+        Integer hours = Integer.parseInt(splitTime[0]);
+        Integer minutes = Integer.parseInt(splitTime[1]);
+
+        String output = new StringBuilder()
+                .append(convertHours(hours))
+                .append(convertMinutes(minutes))
+                .toString();
+
+        return output;
+    }
+
+    public String convertHours(Integer hours) {
+        StringBuilder output = new StringBuilder();
+        if(hours >= 10 && hours < 20) {
+            output.append(timeWords[hours] + " Hundred and ");
+        } else if(hours < 10) {
+            output.append(timeWords[hours / 10]);
+            output.append(" ");
+            output.append(timeWords[hours % 10] + " Hundred and ");
+        } else if(hours > 19) {
+            output.append(tensWords[(hours / 10) - 2]);
+            output.append(" ");
+            output.append(timeWords[hours % 10] + " Hundred and ");
+        }
+        return output.toString();
+    }
+
+    public String convertMinutes(Integer minutes) {
+        StringBuilder output = new StringBuilder();
+        if(minutes > 10 && minutes < 20) {
+            output.append(timeWords[minutes] + " Hours");
+        } else if(minutes < 10) {
+            output.append(timeWords[minutes / 10]);
+            output.append(" ");
+            output.append(timeWords[minutes % 10] + " Hours");
+        } else if(minutes > 19) {
+            output.append(tensWords[(minutes / 10) - 2]);
+            output.append(" ");
+            if(minutes % 10 != 0) {
+                output.append(timeWords[minutes % 10]);
+                output.append(" ");
+            }
+            output.append("Hours");
+        }
+        return output.toString();
+    }
+
+    public String convertNumerically(String time) throws Exception {
+        SimpleDateFormat displayFormat = new SimpleDateFormat("HH:mm");
+        SimpleDateFormat parseFormat = new SimpleDateFormat("hh:mm a");
+        Date date = parseFormat.parse(formatTime(time));
+        return displayFormat.format(date);
+    }
+
+    public String formatTime(String time) {
+        String[] splitTime = time.split("");
+        for(int i = splitTime.length - 1; i > splitTime.length - 4; i--) {
+            if(i == splitTime.length - 3) {
+                splitTime[i] = splitTime[i] + " ";
+            }
+            splitTime[i] = splitTime[i].toUpperCase();
+        }
+        return String.join("", splitTime);
+    }
+}

src/test/java/io/zipcoder/MilitaryTimeTest.java

@@ -0,0 +1,156 @@
+package io.zipcoder;
+
+import org.junit.Assert;
+import org.junit.Before;
+import org.junit.Test;
+
+
+public class MilitaryTimeTest {
+
+    private MilitaryTime militaryTime;
+
+    @Before
+    public void setup() {
+        militaryTime = new MilitaryTime();
+    }
+
+    @Test
+    public void formatTest() {
+        String input = "11:30pm";
+        String expected = "11:30 PM";
+
+        String actual = militaryTime.formatTime(input);
+
+        Assert.assertEquals(expected, actual);
+    }
+
+    @Test
+    public void convertNumericallyPMTest() throws Exception{
+        String input = "1:30pm";
+        String expected = "13:30";
+
+        String actual = militaryTime.convertNumerically(input);
+
+        Assert.assertEquals(expected, actual);
+    }
+
+    @Test
+    public void convertNumericallyAMTest() throws Exception {
+        String input = "1:30am";
+        String expected = "01:30";
+
+        String actual = militaryTime.convertNumerically(input);
+        Assert.assertEquals(expected, actual);
+    }
+
+    @Test
+    public void convertHoursTest() {
+        Integer input = 11;
+        String expected = "Eleven Hundred and ";
+
+        String actual = militaryTime.convertHours(input);
+
+        Assert.assertEquals(expected, actual);
+    }
+
+    @Test
+    public void convertHoursTest2() {
+        Integer input = 23;
+        String expected = "Twenty Three Hundred and ";
+
+        String actual = militaryTime.convertHours(input);
+
+        Assert.assertEquals(expected, actual);
+    }
+
+    @Test
+    public void convertHoursTest3() {
+        Integer input = 58;
+        String expected = "Fifty Eight Hundred and ";
+
+        String actual = militaryTime.convertHours(input);
+
+        Assert.assertEquals(expected, actual);
+    }
+
+    @Test
+    public void convertHoursTest4() {
+        Integer input = 3;
+        String expected = "Zero Three Hundred and ";
+
+        String actual = militaryTime.convertHours(input);
+
+        Assert.assertEquals(expected, actual);
+    }
+
+    @Test
+    public void convertMinutesTest() {
+        Integer input = 3;
+        String expected = "Zero Three Hours";
+
+        String actual = militaryTime.convertMinutes(input);
+
+        Assert.assertEquals(expected, actual);
+    }
+
+    @Test
+    public void convertMinutesTest2() {
+        Integer input = 14;
+        String expected = "Fourteen Hours";
+
+        String actual = militaryTime.convertMinutes(input);
+
+        Assert.assertEquals(expected, actual);
+    }
+
+    @Test
+    public void militaryTimePM() throws Exception {
+        String input = "1:30pm";
+        String expected = "Thirteen Hundred and Thirty Hours";
+
+        String actual = militaryTime.convertToMilitaryTime(input);
+
+        Assert.assertEquals(expected, actual);
+    }
+
+    @Test
+    public void militaryTimePM2() throws Exception {
+        String input = "2:22pm";
+        String expected = "Fourteen Hundred and Twenty Two Hours";
+
+        String actual = militaryTime.convertToMilitaryTime(input);
+
+        Assert.assertEquals(expected, actual);
+    }
+
+    @Test
+    public void militaryTimeAM() throws Exception {
+        String input = "1:30am";
+        String expected = "Zero One Hundred and Thirty Hours";
+
+        String actual = militaryTime.convertToMilitaryTime(input);
+
+        Assert.assertEquals(expected, actual);
+    }
+
+    @Test
+    public void militaryTimeAM2() throws Exception {
+        String input = "2:11am";
+        String expected = "Zero Two Hundred and Eleven Hours";
+
+        String actual = militaryTime.convertToMilitaryTime(input);
+
+        Assert.assertEquals(expected, actual);
+    }
+
+    @Test
+    public void militaryTimeAM3() throws Exception {
+        String input = "10:02am";
+        String expected = "Ten Hundred and Zero Two Hours";
+
+        String actual = militaryTime.convertToMilitaryTime(input);
+
+        Assert.assertEquals(expected, actual);
+    }
+
+}