fix final backend and styling

lib/actions.ts

@@ -4,18 +4,21 @@ import { z } from "zod";
 import { oldestDate, signupFormSchema, youngestDate } from "@/app/sign-up/sign-up-form";
 import listmonk, { listmonkData } from "./listmonk";
 
-export async function signupFormSubmit(data: z.infer<typeof signupFormSchema>) {
+export async function signupFormSubmit(data: z.infer<typeof signupFormSchema>): Promise<string> {
   if (data.dob > youngestDate || data.dob < oldestDate) {
-    return { error: "Invalid date of birth" };
+    return "Invalid date of birth";
   }
+  const offset = data.dob.getTimezoneOffset();
+  data.dob = new Date(data.dob.getTime() - offset * 60 * 1000);
+
   const listmonkData: listmonkData = {
     email: data.email,
     name: data.name,
     status: "enabled",
     lists: [6],
     attribs: {
-      dob: data.dob.toISOString(),
+      dob: data.dob.toISOString().split("T")[0],
     },
   };
-  listmonk(listmonkData);
+  return await listmonk(listmonkData);
 }