Add Nowstore

frontend/src/lib/store/nowStore.ts

@@ -0,0 +1,24 @@
+import { type Writable, writable } from "svelte/store";
+
+async function createStore(): Promise<Writable<Date> & { next: Function; prev: Function }> {
+	const { subscribe, update, set } = writable(new Date());
+	return {
+		subscribe,
+		update,
+		set,
+		next: () => {
+			update((now: Date) => {
+				now.setMonth(now.getMonth() + 1);
+				return now
+			});
+		},
+		prev: () => {
+			update((now: Date) => {
+				now.setMonth(now.getMonth() - 1);
+				return now
+			});
+		},
+	};
+}
+
+export const nowStore = await createStore();