fixed millis in timestamp

app/src/taskmanager.js

@@ -2,7 +2,7 @@ import { invoke } from '@tauri-apps/api';
 
 export class Task {
     async create(name, subject, description, expires_at) {
-        return await invoke("add_task", { name: name, subject: subject, description: description, expiresAt: expires_at });
+        return await invoke("add_task", { name: name, subject: subject, description: description, expiresAt: (parseInt(expires_at) / 1000).toString() });
     }
     async get_batch(limit, page) {
         return await invoke("get_tasks", { limit: limit, page: page });