diff --git a/src/fetchData.js b/src/fetchData.js
index 395b1c2..ac57677 100644
--- a/src/fetchData.js
+++ b/src/fetchData.js
@@ -6,7 +6,7 @@ export default async function fetchData(currentRegionSelection, currentTimeSelec
     const resp = await fetch(urlBuilder(currentRegionSelection, currentTimeSelection, currentAggregateSelection));
     const respData = await resp.json();
     for (let i = 0, l = respData.length; i < l; i++) {
-        let datum = new Datum(Date.parse(respData[i][0]), respData[i][1]);
+        const datum = new Datum(new Date(respData[i][0]), respData[i][1]);
         data.push(datum);
     }
     return data;
diff --git a/src/index.html b/src/index.html
index ffd26d0..5a0c4a6 100644
--- a/src/index.html
+++ b/src/index.html
@@ -62,6 +62,12 @@
                                 <option id='agg_davg' value="avg">Daily Average</option>
                             </select>
                         </fieldset>
+                        <fieldset id="period-overlay-options">
+                            <label for="period-overlay" id="period-overlay-label">
+                                Overlay previous <em id="period-time">0 hours</em> on current period:
+                            </label>
+                            <input type="checkbox" id="period-overlay" name="period-overlay">
+                        </fieldset>
                         <fieldset id="y-start-options">
                             <label for="y-start">Start y-axis at 0:</label>
                             <input type="checkbox" id="y-start" name="y-start"/>
diff --git a/src/index.js b/src/index.js
index 3263aaa..51c0e53 100644
--- a/src/index.js
+++ b/src/index.js
@@ -6,6 +6,7 @@ import fetchData from "./fetchData";
 import {updateHighTime} from "./highTime";
 import {updateLowTime} from "./lowTime";
 import {addLoader, removeLoader} from "./loader";
+import {allowOverlay, forceOverlayOff, isOverlaySelected} from "./overlay";
 import TokenChart from "./tokenChart";
 import Datum from "./datum";
 
@@ -66,7 +67,6 @@ async function updateRegionPreference(newRegion) {
         currentRegionSelection = newRegion;
     }
     formatToken();
-    chart = new TokenChart();
     await pullChartData();
 }
 
@@ -76,7 +76,12 @@ async function updateTimePreference(newTime) {
         addLoader();
         currentTimeSelection = newTime;
     }
-    chart = new TokenChart();
+    if (newTime === "all") {
+        forceOverlayOff();
+    }
+    else {
+        allowOverlay();
+    }
     await pullChartData();
     updateHighTime();
     updateLowTime();
@@ -88,7 +93,6 @@ async function updateAggregatePreference(newAggregate) {
         addLoader();
         currentAggregateSelection = newAggregate;
     }
-    chart = new TokenChart();
     await pullChartData();
 }
 
@@ -109,16 +113,28 @@ function toggleStartYAtZero(){
     chart.toggleYStart(startYAtZero);
 }
 
+async function toggleOverlay() {
+    await chart.destroyChart();
+    addLoader();
+    await pullChartData();
+}
+
 async function pullChartData() {
-    chartData[currentRegionSelection] = await fetchData(currentRegionSelection, currentTimeSelection, currentAggregateSelection);
+    let timeSelection = currentTimeSelection;
+    if (isOverlaySelected()) {
+        let timeDigits = parseInt(timeSelection.slice(0, timeSelection.length - 1)) * 2;
+        let timeUnit = timeSelection.slice(timeSelection.length - 1);
+        timeSelection = `${timeDigits}${timeUnit}`;
+    }
+    chartData[currentRegionSelection] = await fetchData(currentRegionSelection, timeSelection, currentAggregateSelection);
     if (!chart.active()) {
         await chart.createChart(currentRegionSelection, currentTimeSelection, startYAtZero, chartData[currentRegionSelection]);
     }
     else {
         for (let i = 0; i < chartData[currentRegionSelection].length; i++) {
             await chart.addDataToChart(chartData[currentRegionSelection][i]);
-            console.warn("This should never hit, and should be okay to remove");
         }
+        console.warn("This should never hit, and should be okay to remove");
     }
     removeLoader();
 }
@@ -151,6 +167,9 @@ function detectTimeQuery(urlSearchParams) {
     const validTimes = ['72h', '168h', '336h', '720h', '30d', '2190h', '90d', '1y', '2y', '6m', 'all'];
     if (validTimes.includes(urlSearchParams.get('time').toLowerCase())) {
         currentTimeSelection = urlSearchParams.get('time').toLowerCase();
+        if (currentTimeSelection === 'all') {
+            forceOverlayOff();
+        }
         let timeDDL = document.getElementById('time');
         for (let i = 0; i < timeDDL.options.length; i++) {
             if (timeDDL.options[i].value === currentTimeSelection) {
@@ -249,6 +268,8 @@ function registerEventHandles() {
     registerAdvancedHandlers();
 }
 
+// TODO: These need to be moved out into probably tokenChart if not other files
+
 function registerAdvancedHandlers() {
     document.getElementById('enable-advanced').addEventListener('change', () => {
         toggleAdvancedSetting();
@@ -256,6 +277,9 @@ function registerAdvancedHandlers() {
     document.getElementById('y-start').addEventListener('change', () => {
         toggleStartYAtZero();
     })
+    document.getElementById('period-overlay').addEventListener('change', () => {
+        toggleOverlay();
+    })
 }
 
 function registerCopyHandlers() {
diff --git a/src/overlay.js b/src/overlay.js
new file mode 100644
index 0000000..9300a98
--- /dev/null
+++ b/src/overlay.js
@@ -0,0 +1,27 @@
+function isOverlaySelected() {
+    return document.getElementById('period-overlay').checked;
+}
+
+function getOverlayTime() {
+    return document.getElementById("time").selectedOptions[0].innerText;
+}
+
+function setOverlayLabelTime() {
+    const currentTime = document.getElementById("time").selectedOptions[0].innerText;
+    let overlayTimeLabel = document.getElementById("period-time");
+    overlayTimeLabel.innerText = currentTime.toLocaleString();
+}
+
+function forceOverlayOff(){
+    const overlaySetting = document.getElementById("period-overlay");
+    const periodOverlayField = document.getElementById("period-overlay-options");
+    overlaySetting.checked = false;
+    periodOverlayField.style.display = 'none';
+}
+
+function allowOverlay(){
+    const periodOverlayField = document.getElementById("period-overlay-options");
+    periodOverlayField.style.display = 'flex';
+}
+
+export {isOverlaySelected, getOverlayTime, setOverlayLabelTime, forceOverlayOff, allowOverlay};
\ No newline at end of file
diff --git a/src/tokenChart.js b/src/tokenChart.js
index ecee38f..97edbe2 100644
--- a/src/tokenChart.js
+++ b/src/tokenChart.js
@@ -24,6 +24,7 @@ Chart.register(
 
 import {updateHighVal} from "./highTime";
 import {updateLowVal} from "./lowTime";
+import {isOverlaySelected, getOverlayTime, setOverlayLabelTime} from "./overlay";
 
 function lookupTimeUnit(query){
     const lookup = {
@@ -36,6 +37,24 @@ function lookupTimeUnit(query){
     return lookup[query.charAt(query.length - 1)]
 }
 
+function timeDeltaInMilliseconds(time) {
+    let timeDigits = (parseInt(time.slice(0, time.length - 1))).toFixed(0);
+    let timeUnit = time.slice(time.length - 1);
+
+    switch (timeUnit) {
+        case 'h':
+            return timeDigits * (60 * 60) * 1000;
+        case 'd':
+            return timeDigits * (24 * 60 * 60) * 1000;
+        case 'm':
+            return (timeDigits * (30.437 * 24 * 60 * 60)).toFixed(0) * 1000;
+        case 'y':
+            return (timeDigits * (365.25 * 24 * 60 * 60)).toFixed(0) * 1000;
+        case 'l':
+            console.warn("This path should not happen, this warning is an error in logic")
+    }
+}
+
 export default class TokenChart {
     constructor() {
         this._context = document.getElementById("token-chart").getContext('2d');
@@ -54,9 +73,104 @@ export default class TokenChart {
         return this._lowDatum;
     }
 
-    async createChart(region, time, yLevel, data) {
+    async #newChart(chartConfig) {
+        this._chart = new Chart(this._context, chartConfig);
+    }
+
+    async #createOverlayChart(region, time, yLevel, data){
         const chartData = [];
-        let lateUpdateData = this._lastDatum;
+        const overlayData = [];
+        const overlayDelta = timeDeltaInMilliseconds(time);
+
+        for (let i = 0; i < data.length; i++) {
+            const originalDate = data[i].getX();
+            if (i < (data.length / 2)) {
+                overlayData.push({
+                    x: new Date(originalDate.getTime() + overlayDelta),
+                    y: data[i].getY(),
+                });
+            }
+            else {
+
+                this._lastDatum = data[i];
+                if (this._highDatum === null || this._lastDatum.getPrice() > this._highDatum.getPrice()) {
+                    this._highDatum = data[i];
+                }
+
+                if (this._lowDatum === null || this._lowDatum.getPrice() > this._lastDatum.getPrice()) {
+                    this._lowDatum = data[i];
+                }
+
+                chartData.push({
+                    x: data[i].getX(),
+                    y: data[i].getY(),
+                })
+            }
+        }
+
+        const chartConfig = {
+            type: 'line',
+            data: {
+                datasets: [
+                    {
+                        borderColor: 'gold',
+                        label: region.toUpperCase() + " WoW Token Price",
+                        data: chartData,
+                        cubicInterpolationMode: 'monotone',
+                        pointRadius: 0
+                    },
+                    {
+                        borderColor: 'red',
+                        label: `Previous ${getOverlayTime()} ${region.toUpperCase()} WoW Token Price`,
+                        data: overlayData,
+                        cubicInterpolationMode: 'monotone',
+                        pointRadius: 0
+                    }
+                ]
+            },
+            options: {
+                interaction: {
+                    intersect: false,
+                    mode: "index"
+                },
+                scales: {
+                    x: {
+                        type: 'time',
+                        grid: {
+                            color: '#625f62',
+                        },
+                        ticks: {
+                            color: '#a7a4ab',
+                            font: {
+                                size: 18,
+                            }
+                        },
+                        time: {
+                            unit: lookupTimeUnit(time)
+                        }
+                    },
+                    y: {
+                        beginAtZero: yLevel,
+                        grid: {
+                            color: '#2f2c2f',
+                        },
+                        ticks: {
+                            color: '#a7a4ab',
+                            font: {
+                                size: 18,
+                            }
+                        }
+                    }
+                },
+            }
+        }
+
+        await this.#newChart(chartConfig)
+    }
+
+    async #createNormalChart(region, time, yLevel, data) {
+        const chartData = [];
+
 
         for (let i = 0; i < data.length; i++) {
             this._lastDatum = data[i];
@@ -74,10 +188,7 @@ export default class TokenChart {
             })
         }
 
-        updateHighVal(this.highDatum);
-        updateLowVal(this.lowDatum);
-
-        this._chart = new Chart(this._context, {
+        const chartConfig = {
             type: 'line',
             data: {
                 datasets: [{
@@ -123,7 +234,25 @@ export default class TokenChart {
                     }
                 },
             }
-        });
+        }
+
+        await this.#newChart(chartConfig)
+    }
+
+    async createChart(region, time, yLevel, data) {
+        let lateUpdateData = this._lastDatum;
+
+        if (isOverlaySelected()) {
+            await this.#createOverlayChart(region, time, yLevel, data)
+        }
+        else {
+            await this.#createNormalChart(region, time, yLevel, data)
+        }
+
+        setOverlayLabelTime();
+
+        updateHighVal(this.highDatum);
+        updateLowVal(this.lowDatum);
 
         if (this._lateUpdate) {
             if (this._lastDatum.getPrice() !== lateUpdateData.getPrice() &&
@@ -160,12 +289,7 @@ export default class TokenChart {
             this._lowDatum = datum;
             updateLowVal(this.lowDatum);
         }
-        this._chart.data.datasets.forEach((dataset) => {
-            dataset.data.push({
-                x: datum.getX(),
-                y: datum.getY(),
-            })
-        });
+        this._chart.data.datasets[0].data.push(datum);
         this._chart.update();
     }