fix today being berlin timezone

src/grist/service.ts

@@ -4,6 +4,7 @@ import {
 	logWarning,
 	type ServiceResult,
 } from "@dpu/shared";
+import { DateTime } from "luxon";
 import { Config } from "../config.js";
 import type { GristClient } from "./client.js";
 
@@ -35,9 +36,13 @@ export class GristService extends BaseService<GristClient> {
 		}
 	}
 
-	private getTodayAsId(date = new Date()) {
-		const start = new Date(date.getFullYear(), 0, 0);
-		const diff = date.getTime() - start.getTime();
+	private getTodayAsId() {
+		const now = DateTime.now().setZone("Europe/Berlin");
+		const start = DateTime.fromObject(
+			{ year: now.year, month: 0, day: 0, hour: 0, minute: 0 },
+			{ zone: "Europe/Berlin" },
+		);
+		const diff = start.diff(now).toMillis();
 		return Math.floor(diff / 86400000);
 	}