diff --git a/types/event-calendar__core/event-calendar__core-tests.ts b/types/event-calendar__core/event-calendar__core-tests.ts
index 2f3e1d753936dc..0328a3d3fff4ec 100644
--- a/types/event-calendar__core/event-calendar__core-tests.ts
+++ b/types/event-calendar__core/event-calendar__core-tests.ts
@@ -169,6 +169,8 @@ cal = createCalendar(target, plugins, {
     eventLongPressDelay: 100,
     eventMouseEnter: (_info: Calendar.MouseEnterInfo) => {},
     eventMouseLeave: (_info: Calendar.MouseEnterInfo) => {},
+    eventOrder: (_a: Calendar.EventOrderInfo, _b: Calendar.EventOrderInfo) => 0,
+    eventResizableFromStart: true,
     eventResize: (_info: Calendar.EventResizeInfo) => {},
     eventResizeStart: (_info: Calendar.EventDuringResizeInfo) => {},
     eventResizeStop: (_info: Calendar.EventDuringResizeInfo) => {},
@@ -256,6 +258,11 @@ cal = createCalendar(target, plugins, {
 cal.setOption("buttonText", () => {
     return { baz: "bux" };
 })
+    .setOption("customButtons", (customButtons: Calendar.CustomButtons) => {
+        customButtons.foo = { text: "Foo", click: () => null };
+        customButtons.bar = { text: "Bar", active: false, click: () => undefined };
+        return customButtons;
+    })
     .setOption("dayCellFormat", (_d: Date) => "content")
     .setOption("dayHeaderAriaLabelFormat", (_d: Date) => "content")
     .setOption("dayHeaderFormat", (_d: Date) => "content")
diff --git a/types/event-calendar__core/index.d.ts b/types/event-calendar__core/index.d.ts
index aec1f1057a0efd..5862c26adef394 100644
--- a/types/event-calendar__core/index.d.ts
+++ b/types/event-calendar__core/index.d.ts
@@ -55,6 +55,10 @@ export namespace Calendar {
         active?: boolean;
     }
 
+    interface CustomButtons {
+        [key: string]: CustomButton;
+    }
+
     interface View {
         type: string;
         title: string;
@@ -177,6 +181,12 @@ export namespace Calendar {
         view: View;
     }
 
+    interface EventOrderInfo {
+        start: Date;
+        end: Date;
+        event: Event;
+    }
+
     interface EventResizeInfo {
         event: Event;
         oldEvent: Event;
@@ -299,7 +309,7 @@ export namespace Calendar {
         allDayContent?: Content;
         allDaySlot?: boolean;
         buttonText?: ButtonTextMapping | ((text: ButtonTextMapping) => ButtonTextMapping);
-        customButtons?: Record<string, CustomButton>;
+        customButtons?: CustomButtons | ((customButtons: CustomButtons) => CustomButtons);
         date?: Date | string | undefined;
         dateClick?: (info: DateClickInfo) => void;
         datesAboveResources?: boolean;
@@ -331,6 +341,8 @@ export namespace Calendar {
         eventLongPressDelay?: number;
         eventMouseEnter?: (info: MouseEnterInfo) => void;
         eventMouseLeave?: (info: MouseEnterInfo) => void;
+        eventOrder?: (a: EventOrderInfo, b: EventOrderInfo) => number;
+        eventResizableFromStart?: boolean;
         eventResize?: (info: EventResizeInfo) => void;
         eventResizeStart?: (info: EventDuringResizeInfo) => void;
         eventResizeStop?: (info: EventDuringResizeInfo) => void;
diff --git a/types/event-calendar__core/package.json b/types/event-calendar__core/package.json
index ebd69f5b5192dc..8060a5eb78dca5 100644
--- a/types/event-calendar__core/package.json
+++ b/types/event-calendar__core/package.json
@@ -2,7 +2,7 @@
     "private": true,
     "type": "module",
     "name": "@types/event-calendar__core",
-    "version": "4.4.9999",
+    "version": "4.7.9999",
     "projects": [
         "https://vkurko.github.io/calendar/"
     ],