diff --git a/.devcontainer/ui-lovelace.yaml b/.devcontainer/ui-lovelace.yaml
index d9fb978..e062dd5 100644
--- a/.devcontainer/ui-lovelace.yaml
+++ b/.devcontainer/ui-lovelace.yaml
@@ -866,7 +866,19 @@ views:
                 show:
                   in_brush: true
                   in_chart: false
-          - type: entities
-            title: test
-            entities:
-              - sensor.random0_100
+          - type: custom:apexcharts-card
+            graph_span: 1h
+            all_series_config:
+              type: column
+            series:
+              - entity: sensor.random0_100
+                name: last
+                group_by:
+                  func: last
+                  duration: 10min
+              - entity: sensor.random0_100
+                name: first
+                group_by:
+                  func: first
+                  duration: 10min
+                  start_with_last: true
diff --git a/README.md b/README.md
index a161753..501006b 100644
--- a/README.md
+++ b/README.md
@@ -223,6 +223,7 @@ The position of the marker will only update when the card updates (state change
 | `func` | string | `raw` | v1.0.0 | See [func](#func-options) |
 | `duration` | string | `1h` | v1.0.0 | If `func` is **not** `raw` only. It builds buckets of states over `duration` period of time. Doesn't work for months. Eg of valid values: `2h`, `1d`, `10s`, `25min`, `1h30`, ... |
 | `fill` | string | `last` | v1.0.0 | If `func` is **not** `raw` only. If there is any missing value in the buckets of history data (grouped by duration), `last` will replace them with the last non-empty state, `zero` will fill missing values with `0`, `'null'` will fill missing values with `null` |
+| `start_with_last` | boolean | `false` | NEXT_VERSION | If `true`, each bucket of data will start with the last value from the previous bucket of data. Mostly useful only with `func: diff` |
 
 ### `func` Options
 
diff --git a/src/graphEntry.ts b/src/graphEntry.ts
index 6b839ca..c003cbd 100644
--- a/src/graphEntry.ts
+++ b/src/graphEntry.ts
@@ -371,8 +371,7 @@ export default class GraphEntry {
       }
 
       buckets.some((bucket, index) => {
-        // eslint-disable-next-line @typescript-eslint/no-non-null-assertion
-        if (bucket.timestamp > properEntry![0] && index > 0) {
+        if (bucket.timestamp > properEntry[0] && index > 0) {
           buckets[index - 1].data.push(properEntry);
           return true;
         }
@@ -381,7 +380,7 @@ export default class GraphEntry {
     });
     let lastNonNullBucketValue: number | null = null;
     const now = new Date().getTime();
-    buckets.forEach((bucket) => {
+    buckets.forEach((bucket, index) => {
       if (bucket.data.length === 0) {
         if (this._config.group_by.fill === 'last' && bucket.timestamp <= now) {
           bucket.data[0] = [bucket.timestamp, lastNonNullBucketValue];
@@ -393,6 +392,22 @@ export default class GraphEntry {
       } else {
         lastNonNullBucketValue = bucket.data.slice(-1)[0][1];
       }
+      if (this._config.group_by.start_with_last) {
+        if (index > 0) {
+          if (bucket.data[0][0] !== bucket.timestamp) {
+            const prevBucketData = buckets[index - 1].data;
+            bucket.data.unshift([bucket.timestamp, prevBucketData[prevBucketData.length - 1][1]]);
+          }
+        } else {
+          const firstIndexAfter = history.data.findIndex((entry) => {
+            if (entry[0] > bucket.timestamp) return true;
+            return false;
+          });
+          if (firstIndexAfter > 0) {
+            bucket.data.unshift([bucket.timestamp, history.data[firstIndexAfter - 1][1]]);
+          }
+        }
+      }
     });
     buckets.pop();
     while (
diff --git a/src/types-config-ti.ts b/src/types-config-ti.ts
index 369cc2f..a9d5d54 100644
--- a/src/types-config-ti.ts
+++ b/src/types-config-ti.ts
@@ -88,6 +88,7 @@ export const ChartCardAllSeriesExternalConfig = t.iface([], {
     "duration": t.opt("string"),
     "func": t.opt("GroupByFunc"),
     "fill": t.opt("GroupByFill"),
+    "start_with_last": t.opt("boolean"),
   })),
   "transform": t.opt("string"),
   "color_threshold": t.opt(t.array("ChartCardColorThreshold")),
diff --git a/src/types-config.ts b/src/types-config.ts
index a26b8f1..62ad498 100644
--- a/src/types-config.ts
+++ b/src/types-config.ts
@@ -87,6 +87,7 @@ export interface ChartCardAllSeriesExternalConfig {
     duration?: string;
     func?: GroupByFunc;
     fill?: GroupByFill;
+    start_with_last?: boolean;
   };
   transform?: string;
   color_threshold?: ChartCardColorThreshold[];
diff --git a/src/types.ts b/src/types.ts
index 0fd5ab0..8dcbe22 100644
--- a/src/types.ts
+++ b/src/types.ts
@@ -23,6 +23,7 @@ export interface ChartCardSeriesConfig extends ChartCardSeriesExternalConfig {
     duration: string;
     func: GroupByFunc;
     fill: GroupByFill;
+    start_with_last?: boolean;
   };
   show: {
     as_duration?: ChartCardPrettyTime;