diff --git a/pom.xml b/pom.xml
index f48d24a..a661852 100644
--- a/pom.xml
+++ b/pom.xml
@@ -12,7 +12,7 @@
 
     <properties>
         <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
-        <kotlin.version>1.3.10</kotlin.version>
+        <kotlin.version>1.3.11</kotlin.version>
         <kotlin.code.style>official</kotlin.code.style>
         <junit.version>4.12</junit.version>
     </properties>
diff --git a/src/main/kotlin/com/basdado/adventofcode/Day4.kt b/src/main/kotlin/com/basdado/adventofcode/Day4.kt
index db7fb2d..15f97e2 100644
--- a/src/main/kotlin/com/basdado/adventofcode/Day4.kt
+++ b/src/main/kotlin/com/basdado/adventofcode/Day4.kt
@@ -71,7 +71,7 @@ class Day4 {
 
     private fun parseGuardDays(sortedLines: MutableList<Line>): List<GuardDay> {
         val guardDays = mutableListOf<GuardDay>()
-        var currentDay = GuardDay(0, LocalDate.EPOCH, mutableListOf())
+        var currentDay = GuardDay(0, LocalDate.MIN, mutableListOf())
         var sleepStartMinute = 0
         for (line in sortedLines) {
             if (line.event == GuardEventType.BEGIN_SHIFT) {
diff --git a/src/main/kotlin/com/basdado/adventofcode/Day6Extra.kt b/src/main/kotlin/com/basdado/adventofcode/Day6Extra.kt
new file mode 100644
index 0000000..7d2ae4e
--- /dev/null
+++ b/src/main/kotlin/com/basdado/adventofcode/Day6Extra.kt
@@ -0,0 +1,2 @@
+package com.basdado.adventofcode
+
diff --git a/src/main/kotlin/com/basdado/adventofcode/Day7.kt b/src/main/kotlin/com/basdado/adventofcode/Day7.kt
new file mode 100644
index 0000000..f0f0672
--- /dev/null
+++ b/src/main/kotlin/com/basdado/adventofcode/Day7.kt
@@ -0,0 +1,168 @@
+package com.basdado.adventofcode
+
+import java.lang.IllegalStateException
+import java.lang.Integer.min
+import java.util.Arrays.stream
+import java.util.stream.Collectors
+import java.util.stream.IntStream
+
+fun main() {
+
+    val day = Day7()
+    day.puzzle1()
+    day.puzzle2()
+}
+
+class Day7 {
+
+    fun puzzle1() {
+
+        val graph = loadGraph()
+
+        val nodeOrder = mutableListOf<Node>()
+        val availableNodes = graph.nodes.filter { n -> n.previous.isEmpty() }.toMutableSet()
+
+        while (!availableNodes.isEmpty()) {
+            val nextNode = availableNodes.sortedBy { n -> n.id }[0]
+            nodeOrder.add(nextNode)
+            availableNodes.remove(nextNode)
+            availableNodes.addAll(nextNode.next
+                .filter { !nodeOrder.contains(it) }
+                .filter { nodeOrder.containsAll(it.previous) })
+        }
+
+        println(nodeOrder.stream().map{ it.id }.collect(Collectors.joining()))
+    }
+
+    fun puzzle2() {
+
+        val graph = loadGraph()
+
+        val timeline = TimeLine()
+
+        // The first timeslot is available
+//        timeline.add(Array(workerCount) { null })
+        var finished = emptySet<Node>()
+        var availableNodes = graph.nodes.filter { n -> n.previous.isEmpty() }.toMutableSet()
+
+        var time = 0
+        while (!finished.containsAll(graph.nodes)) {
+
+            val orderedAvailableNodes = availableNodes.sortedBy { n -> n.id }
+
+            val timeSlot = timeline.getSlot(time)
+
+            // Divide the available workers
+            for (availableNode in orderedAvailableNodes) {
+                val availableWorkerIndex = timeSlot.indexOfFirst { it == null }
+                if (availableWorkerIndex == -1) {
+                    break
+                }
+                timeline.addJob(time, availableWorkerIndex, availableNode)
+            }
+
+            time++
+            finished = timeline.finishedNodes(time)
+            availableNodes = graph.nodes
+                .filter { finished.containsAll(it.previous) }
+                    // Not finished
+                .filter { !finished.contains(it) }
+                    // Not in progress
+                .filter { !timeline.getSlot(time).contains(it) }
+                .toMutableSet()
+
+        }
+
+//        println(timeline)
+        println(timeline.timeline.size)
+
+    }
+
+    private fun loadGraph(): Graph {
+        val graph = Graph()
+        val lineMatcher = Regex("""Step ([A-Z]) must be finished before step ([A-Z]) can begin.""")
+        lines("/day/7/input.txt")
+            .forEach {
+                val match = lineMatcher.matchEntire(it)!!
+                graph.addConnection(match.groupValues[1], match.groupValues[2])
+            }
+        return graph
+    }
+
+    class TimeLine(val workerCount: Int = 5) {
+        val timeline = mutableListOf<Array<Node?>>()
+
+        fun getSlot(time: Int): Array<Node?> {
+            extendUntil(time)
+            return timeline[time]
+        }
+
+        fun finishedNodes(time: Int): Set<Node> {
+
+            // All jobs that were active before "time" and are no longer active on "time" are finished
+            val finished = mutableSetOf<Node>()
+            for (t in 0 until min(time, timeline.size)) {
+                finished.addAll(timeline[t].filterNotNull())
+            }
+            if (timeline.size > time) {
+                finished.removeAll(timeline[time].filterNotNull())
+            }
+            return finished
+        }
+
+        fun addJob(startTime: Int, workerId: Int, node: Node) {
+
+            extendUntil(startTime + node.processTime())
+            for(time in startTime until startTime + node.processTime()) {
+                if (timeline[time][workerId] != null) {
+                    throw IllegalStateException("Worker $workerId is already busy in timeslot $time")
+                }
+                timeline[time][workerId] = node
+            }
+        }
+
+        fun extendUntil(time: Int) {
+            if (timeline.size > time) {
+                return
+            }
+            for(t in timeline.size..time) {
+                timeline.add(Array(workerCount) { null })
+            }
+        }
+
+        override fun toString(): String {
+            return IntStream.range(0, timeline.size)
+                .mapToObj { "" + it + "    " +
+                        stream(timeline[it]).map{ n -> n?.toString() ?: "." }.collect(Collectors.joining(" ")) + "    " +
+                        finishedNodes(it).map{n -> n.id}.joinToString ( ", " )}
+                .collect(Collectors.joining("\r\n"))
+        }
+    }
+    class Graph {
+
+        val nodes: MutableSet<Node> = mutableSetOf()
+
+        fun addConnection(id1: String, id2: String) {
+            val node1 = findOrCreateNode(id1)
+            val node2 = findOrCreateNode(id2)
+
+            node1.next.add(node2)
+            node2.previous.add(node1)
+        }
+
+        fun findOrCreateNode(id: String): Node {
+            return nodes.stream().filter{ it.id == id }.findAny()
+                .orElseGet {
+                    val newNode = Node(id)
+                    nodes.add(newNode)
+                    newNode
+                }
+        }
+    }
+
+    class Node(val id: String, val next: MutableSet<Node> = mutableSetOf(), val previous: MutableSet<Node> = mutableSetOf()) {
+        fun processTime() = 60 + (id[0] - 'A') + 1
+
+        override fun toString(): String = id
+    }
+}
\ No newline at end of file
diff --git a/src/main/resources/day/6/extra/input.txt b/src/main/resources/day/6/extra/input.txt
new file mode 100644
index 0000000..e69de29
diff --git a/src/main/resources/day/7/input.txt b/src/main/resources/day/7/input.txt
new file mode 100644
index 0000000..7ae58e4
--- /dev/null
+++ b/src/main/resources/day/7/input.txt
@@ -0,0 +1,102 @@
+Step G must be finished before step S can begin.
+Step T must be finished before step Q can begin.
+Step A must be finished before step B can begin.
+Step H must be finished before step X can begin.
+Step V must be finished before step O can begin.
+Step Z must be finished before step P can begin.
+Step R must be finished before step J can begin.
+Step L must be finished before step Y can begin.
+Step Y must be finished before step E can begin.
+Step W must be finished before step X can begin.
+Step X must be finished before step B can begin.
+Step K must be finished before step E can begin.
+Step Q must be finished before step P can begin.
+Step U must be finished before step B can begin.
+Step M must be finished before step O can begin.
+Step P must be finished before step N can begin.
+Step I must be finished before step J can begin.
+Step B must be finished before step C can begin.
+Step C must be finished before step O can begin.
+Step J must be finished before step F can begin.
+Step F must be finished before step O can begin.
+Step E must be finished before step D can begin.
+Step D must be finished before step N can begin.
+Step N must be finished before step S can begin.
+Step S must be finished before step O can begin.
+Step W must be finished before step O can begin.
+Step L must be finished before step P can begin.
+Step N must be finished before step O can begin.
+Step T must be finished before step D can begin.
+Step G must be finished before step I can begin.
+Step V must be finished before step X can begin.
+Step B must be finished before step N can begin.
+Step R must be finished before step N can begin.
+Step H must be finished before step J can begin.
+Step B must be finished before step S can begin.
+Step P must be finished before step I can begin.
+Step A must be finished before step J can begin.
+Step A must be finished before step U can begin.
+Step B must be finished before step D can begin.
+Step T must be finished before step A can begin.
+Step U must be finished before step D can begin.
+Step T must be finished before step L can begin.
+Step I must be finished before step E can begin.
+Step R must be finished before step U can begin.
+Step H must be finished before step S can begin.
+Step P must be finished before step F can begin.
+Step Q must be finished before step C can begin.
+Step A must be finished before step P can begin.
+Step X must be finished before step E can begin.
+Step Q must be finished before step N can begin.
+Step E must be finished before step N can begin.
+Step Q must be finished before step O can begin.
+Step J must be finished before step S can begin.
+Step X must be finished before step P can begin.
+Step K must be finished before step U can begin.
+Step F must be finished before step E can begin.
+Step C must be finished before step E can begin.
+Step H must be finished before step K can begin.
+Step W must be finished before step B can begin.
+Step G must be finished before step O can begin.
+Step F must be finished before step N can begin.
+Step I must be finished before step D can begin.
+Step G must be finished before step V can begin.
+Step E must be finished before step S can begin.
+Step Y must be finished before step P can begin.
+Step G must be finished before step E can begin.
+Step P must be finished before step J can begin.
+Step P must be finished before step J can begin.
+Step U must be finished before step N can begin.
+Step U must be finished before step F can begin.
+Step X must be finished before step U can begin.
+Step X must be finished before step C can begin.
+Step R must be finished before step Q can begin.
+Step Q must be finished before step E can begin.
+Step Z must be finished before step E can begin.
+Step X must be finished before step F can begin.
+Step J must be finished before step D can begin.
+Step X must be finished before step M can begin.
+Step Y must be finished before step D can begin.
+Step K must be finished before step J can begin.
+Step Z must be finished before step J can begin.
+Step M must be finished before step P can begin.
+Step T must be finished before step M can begin.
+Step F must be finished before step S can begin.
+Step P must be finished before step S can begin.
+Step X must be finished before step I can begin.
+Step U must be finished before step J can begin.
+Step M must be finished before step B can begin.
+Step Q must be finished before step D can begin.
+Step Z must be finished before step I can begin.
+Step D must be finished before step S can begin.
+Step J must be finished before step N can begin.
+Step D must be finished before step O can begin.
+Step T must be finished before step H can begin.
+Step P must be finished before step D can begin.
+Step M must be finished before step F can begin.
+Step Y must be finished before step S can begin.
+Step H must be finished before step I can begin.
+Step Y must be finished before step W can begin.
+Step X must be finished before step J can begin.
+Step L must be finished before step W can begin.
+Step G must be finished before step N can begin.
\ No newline at end of file