diff --git a/app/components/Input.tsx b/app/components/Input.tsx
index fb6b3a8b5..87faaf30b 100644
--- a/app/components/Input.tsx
+++ b/app/components/Input.tsx
@@ -2,17 +2,21 @@ import clsx from "clsx";
 
 export function Input({
   name,
-  leftAddon,
   className,
+  minLength,
+  maxLength,
+  leftAddon,
 }: {
   name: string;
-  leftAddon?: string;
   className?: string;
+  minLength?: number;
+  maxLength?: number;
+  leftAddon?: string;
 }) {
   return (
     <div className={clsx("input-container", className)}>
       {leftAddon ? <div className="input-addon">{leftAddon}</div> : null}
-      <input name={name} />
+      <input name={name} minLength={minLength} maxLength={maxLength} />
     </div>
   );
 }
diff --git a/app/constants.ts b/app/constants.ts
index 246ddd23d..7cfe351b7 100644
--- a/app/constants.ts
+++ b/app/constants.ts
@@ -2,9 +2,16 @@ export const TWEET_LENGTH_MAX_LENGTH = 280;
 export const DISCORD_MESSAGE_MAX_LENGTH = 2000;
 
 export const USER_BIO_MAX_LENGTH = DISCORD_MESSAGE_MAX_LENGTH;
+
 export const PlUS_SUGGESTION_FIRST_COMMENT_MAX_LENGTH = 500;
 export const PlUS_SUGGESTION_COMMENT_MAX_LENGTH = TWEET_LENGTH_MAX_LENGTH;
+
+export const CALENDAR_EVENT_NAME_MIN_LENGTH = 2;
+export const CALENDAR_EVENT_NAME_MAX_LENGTH = 100;
 export const CALENDAR_EVENT_DESCRIPTION_MAX_LENGTH = DISCORD_MESSAGE_MAX_LENGTH;
+export const CALENDAR_EVENT_DISCORD_INVITE_CODE_MAX_LENGTH = 50;
+export const CALENDAR_EVENT_BRACKET_URL_MAX_LENGTH = 100;
+export const CALENDAR_EVENT_MAX_AMOUNT_OF_DATES = 5;
 
 export const PLUS_TIERS = [1, 2, 3];
 
diff --git a/app/routes/calendar/new.tsx b/app/routes/calendar/new.tsx
index ec6257b9c..6439a31f5 100644
--- a/app/routes/calendar/new.tsx
+++ b/app/routes/calendar/new.tsx
@@ -7,9 +7,21 @@ import type {
   CalendarEvent,
   CalendarEventTag,
 } from "~/db/types";
-import { CALENDAR_EVENT_DESCRIPTION_MAX_LENGTH } from "~/constants";
+import {
+  CALENDAR_EVENT_BRACKET_URL_MAX_LENGTH,
+  CALENDAR_EVENT_DESCRIPTION_MAX_LENGTH,
+  CALENDAR_EVENT_DISCORD_INVITE_CODE_MAX_LENGTH,
+  CALENDAR_EVENT_MAX_AMOUNT_OF_DATES,
+  CALENDAR_EVENT_NAME_MAX_LENGTH,
+  CALENDAR_EVENT_NAME_MIN_LENGTH,
+} from "~/constants";
 import { Button } from "~/components/Button";
-import { json, type LinksFunction, type LoaderArgs } from "@remix-run/node";
+import {
+  json,
+  type ActionFunction,
+  type LinksFunction,
+  type LoaderArgs,
+} from "@remix-run/node";
 import styles from "~/styles/calendar-new.css";
 import clsx from "clsx";
 import { useTranslation } from "react-i18next";
@@ -22,11 +34,70 @@ import { Tags } from "./components/Tags";
 import { db } from "~/db";
 import { requireUser } from "~/modules/auth";
 import { Badge } from "~/components/Badge";
+import { z } from "zod";
+import {
+  date,
+  falsyToNull,
+  id,
+  processMany,
+  removeDuplicates,
+  safeJSONParse,
+} from "~/utils/zod";
+import { parseRequestFormData } from "~/utils/remix";
+import { dateToYearMonthDayHourMinuteString } from "~/utils/dates";
+
+const MIN_DATE = new Date(Date.UTC(2015, 4, 28));
+
+const MAX_DATE = new Date();
+MAX_DATE.setFullYear(MAX_DATE.getFullYear() + 1);
 
 export const links: LinksFunction = () => {
   return [{ rel: "stylesheet", href: styles }];
 };
 
+const newCalendarEventActionSchema = z.object({
+  name: z
+    .string()
+    .min(CALENDAR_EVENT_NAME_MIN_LENGTH)
+    .max(CALENDAR_EVENT_NAME_MAX_LENGTH),
+  description: z.preprocess(
+    falsyToNull,
+    z.string().max(CALENDAR_EVENT_DESCRIPTION_MAX_LENGTH).nullable()
+  ),
+  dates: z.preprocess(
+    safeJSONParse,
+    z
+      .array(z.preprocess(date, z.date().min(MIN_DATE).max(MAX_DATE)))
+      .min(1)
+      .max(CALENDAR_EVENT_MAX_AMOUNT_OF_DATES)
+  ),
+  bracketUrl: z.string().url().max(CALENDAR_EVENT_BRACKET_URL_MAX_LENGTH),
+  discordInviteCode: z.preprocess(
+    falsyToNull,
+    z.string().max(CALENDAR_EVENT_DISCORD_INVITE_CODE_MAX_LENGTH).nullable()
+  ),
+  tags: z.preprocess(
+    processMany(safeJSONParse, removeDuplicates),
+    z
+      .array(z.string().refine((val) => Object.keys(allTags).includes(val)))
+      .nullable()
+  ),
+  badges: z.preprocess(
+    processMany(safeJSONParse, removeDuplicates),
+    z.array(id).nullable()
+  ),
+});
+
+export const action: ActionFunction = async ({ request }) => {
+  const user = await requireUser(request);
+  const data = await parseRequestFormData({
+    request,
+    schema: newCalendarEventActionSchema,
+  });
+
+  return null;
+};
+
 export const handle = {
   i18n: "calendar",
 };
@@ -64,7 +135,12 @@ function NameInput() {
       <Label htmlFor="name" required>
         Name
       </Label>
-      <input name="name" required />
+      <input
+        name="name"
+        required
+        minLength={CALENDAR_EVENT_NAME_MIN_LENGTH}
+        maxLength={CALENDAR_EVENT_NAME_MAX_LENGTH}
+      />
     </div>
   );
 }
@@ -110,6 +186,13 @@ function DatesInput() {
 
   return (
     <div className="stack md items-start">
+      {dates.length > 0 && (
+        <input
+          type="hidden"
+          name="dates"
+          value={JSON.stringify(dates.map(({ date }) => date.getTime()))}
+        />
+      )}
       <div>
         <Label htmlFor="date" required>
           Dates
@@ -120,6 +203,8 @@ function DatesInput() {
             type="datetime-local"
             value={dateInputValue ?? ""}
             onChange={(e) => setDateInputValue(e.target.value)}
+            min={dateToYearMonthDayHourMinuteString(MIN_DATE)}
+            max={dateToYearMonthDayHourMinuteString(MAX_DATE)}
           />
           <Button
             tiny
@@ -181,7 +266,11 @@ function DiscordLinkInput() {
   return (
     <div className="stack items-start">
       <Label htmlFor="discordInviteCode">Discord server invite URL</Label>
-      <Input name="discordInviteCode" leftAddon="https://discord.gg/" />
+      <Input
+        name="discordInviteCode"
+        leftAddon="https://discord.gg/"
+        maxLength={CALENDAR_EVENT_DISCORD_INVITE_CODE_MAX_LENGTH}
+      />
     </div>
   );
 }
@@ -192,7 +281,12 @@ function BracketUrlInput() {
       <Label htmlFor="bracketUrl" required>
         Bracket URL
       </Label>
-      <input name="bracketUrl" type="url" required />
+      <input
+        name="bracketUrl"
+        type="url"
+        required
+        maxLength={CALENDAR_EVENT_BRACKET_URL_MAX_LENGTH}
+      />
     </div>
   );
 }
@@ -200,6 +294,7 @@ function BracketUrlInput() {
 function TagsAdder() {
   const { t } = useTranslation("calendar");
   const [tags, setTags] = React.useState<CalendarEventTag[]>([]);
+  const id = React.useId();
 
   const tagsForSelect = (
     Object.keys(allTags) as Array<CalendarEventTag>
@@ -207,10 +302,15 @@ function TagsAdder() {
 
   return (
     <div className="stack sm">
+      <input
+        type="hidden"
+        name="tags"
+        value={JSON.stringify(tags.length > 0 ? tags : null)}
+      />
       <div>
-        <label htmlFor="tags">Tags</label>
+        <label htmlFor={id}>Tags</label>
         <select
-          id="tags"
+          id={id}
           className="calendar-new__select"
           onChange={(e) =>
             setTags([...tags, e.target.value as CalendarEventTag])
@@ -235,6 +335,7 @@ function TagsAdder() {
 function BadgesAdder() {
   const { managedBadges } = useLoaderData<typeof loader>();
   const [badges, setBadges] = React.useState<BadgeType[]>([]);
+  const id = React.useId();
 
   if (managedBadges.length === 0) return null;
 
@@ -248,10 +349,17 @@ function BadgesAdder() {
 
   return (
     <div className="stack md">
+      <input
+        type="hidden"
+        name="badges"
+        value={JSON.stringify(
+          badges.length > 0 ? badges.map((b) => b.id) : null
+        )}
+      />
       <div>
-        <label htmlFor="badges">Badge prizes</label>
+        <label htmlFor={id}>Badge prizes</label>
         <select
-          id="badges"
+          id={id}
           className="calendar-new__select"
           onChange={(e) => {
             setBadges([
diff --git a/app/utils/dates.ts b/app/utils/dates.ts
index 23f2ef73e..01d4827c8 100644
--- a/app/utils/dates.ts
+++ b/app/utils/dates.ts
@@ -33,3 +33,8 @@ export function weekNumberToDate({
   }
   return result;
 }
+
+/** Returns date as a string with the format YYYY-MM-DDThh:mm */
+export function dateToYearMonthDayHourMinuteString(date: Date) {
+  return date.toISOString().slice(0, 16);
+}
diff --git a/app/utils/zod.ts b/app/utils/zod.ts
index 9b168bb23..a81dfd67e 100644
--- a/app/utils/zod.ts
+++ b/app/utils/zod.ts
@@ -2,6 +2,20 @@ import { z } from "zod";
 
 export const id = z.number().int().positive();
 
+export function processMany(
+  ...processFuncs: Array<(value: unknown) => unknown>
+) {
+  return (value: unknown) => {
+    let result = value;
+
+    for (const processFunc of processFuncs) {
+      result = processFunc(result);
+    }
+
+    return result;
+  };
+}
+
 export function safeJSONParse(value: unknown): unknown {
   try {
     if (typeof value !== "string") return value;
@@ -24,6 +38,20 @@ export function actualNumber(value: unknown) {
   return Number.isNaN(parsed) ? undefined : parsed;
 }
 
+export function date(value: unknown) {
+  if (typeof value === "string" || typeof value === "number") {
+    return new Date(value);
+  }
+
+  return value;
+}
+
 export function noDuplicates(arr: (number | string)[]) {
   return new Set(arr).size === arr.length;
 }
+
+export function removeDuplicates(value: unknown) {
+  if (!Array.isArray(value)) return value;
+
+  return Array.from(new Set(value));
+}