diff --git a/packages/frontend/src/components/MkEventEditor.vue b/packages/frontend/src/components/MkEventEditor.vue
new file mode 100644
index 0000000000..ec7ee1cb2d
--- /dev/null
+++ b/packages/frontend/src/components/MkEventEditor.vue
@@ -0,0 +1,183 @@
+<template>
+<div class="zmdxowut">
+	<MkInput v-model="title" small type="text" class="input">
+		<template #label>*{{ "Title" }}</template>
+	</MkInput>
+	<section>
+		<div>
+			<section>
+				<MkInput v-model="startDate" small type="date" class="input">
+					<template #label>*{{ "Start Date" }}</template>
+				</MkInput>
+				<MkInput v-model="startTime" small type="time" class="input">
+					<template #label>*{{ "Start Time" }}</template>
+				</MkInput>
+			</section>
+			<section>
+				<MkInput v-model="endDate" small type="date" class="input">
+					<template #label>{{ "End Date" }}</template>
+				</MkInput>
+				<MkInput v-model="endTime" small type="time" class="input">
+					<template #label>{{ "End Time" }}</template>
+				</MkInput>
+			</section>
+		</div>
+	</section>
+	<p>Details</p>
+	<ul>
+		<li v-for="(entry, i) in meta" :key="i">
+			<MkInput class="input" small :model-value="entry[0]" placeholder="placeholder key"
+				@update:model-value="onKeyInput(i, $event)">
+			</MkInput>
+			<MkInput class="input" small :model-value="entry[1]" placeholder="placeholder value"
+				@update:model-value="onValueInput(i, $event)">
+			</MkInput>
+			<button class="_button" @click="remove(i)">
+				<i class="ti ti-x"></i>
+			</button>
+		</li>
+	</ul>
+	<MkButton class="add" @click="add">{{ i18n.ts.add }}</MkButton>
+</div>
+</template>
+
+<script lang="ts" setup>
+import { Ref, ref, watch } from 'vue';
+import MkInput from './MkInput.vue';
+import MkButton from './MkButton.vue';
+import { formatDateTimeString } from '@/scripts/format-time-string';
+import { addTime } from '@/scripts/time';
+import { i18n } from '@/i18n';
+
+const props = defineProps<{
+	modelValue: {
+		title: string,
+		start: string,
+		end: string | null,
+		metadata: Record<string, string>,
+	}
+}>();
+
+const emit = defineEmits<{
+	(ev: 'update:modelValue', v: {
+		title: string,
+		start: string,
+		end: string | null,
+		metadata: Record<string, string>,
+	})
+}>();
+
+const title = ref(props.modelValue.title);
+const startDate = ref(formatDateTimeString(addTime(new Date(), 1, 'day'), 'yyyy-MM-dd'));
+const startTime = ref('00:00');
+const endDate = ref('');
+const endTime = ref('');
+const meta = ref(Object.entries(props.modelValue.metadata));
+
+function add() {
+	meta.value.push(['', '']);
+}
+
+function onKeyInput(i, newKey) {
+	meta.value[i][0] = newKey;
+}
+
+function onValueInput(i, value) {
+	meta.value[i][1] = value;
+}
+
+function remove(i) {
+	meta.value.splice(i, 1);
+}
+
+function get() {
+	const calcAt = (date: Ref<string>, time: Ref<string>): number => (new Date(`${date.value} ${time.value}`)).getTime();
+
+	return {
+		title: title.value,
+		start: calcAt(startDate, startTime),
+		end: endDate.value ? calcAt(endDate, endTime) : null,
+		metadata: meta.value.reduce((obj, [k, v]) => ({ ...obj, [k]: v }), {}),
+	};
+}
+
+watch([title, startDate, startTime, endDate, endTime, meta], () => emit('update:modelValue', get()), {
+	deep: true,
+});
+</script>
+
+<style lang="scss" scoped>
+.zmdxowut {
+	padding: 8px 16px;
+
+	>.caution {
+		margin: 0 0 8px 0;
+		font-size: 0.8em;
+		color: #f00;
+
+		>i {
+			margin-right: 4px;
+		}
+	}
+
+	>ul {
+		display: block;
+		margin: 0;
+		padding: 0;
+		list-style: none;
+
+		>li {
+			display: flex;
+			margin: 8px 0;
+			padding: 0;
+			width: 100%;
+
+			>.input {
+				flex: 1;
+			}
+
+			>button {
+				width: 32px;
+				padding: 4px 0;
+			}
+		}
+	}
+
+	>.add {
+		margin: 8px 0;
+		z-index: 1;
+	}
+
+	>section {
+		margin: 16px 0 0 0;
+
+		>div {
+			margin: 0 8px;
+			display: flex;
+			flex-direction: row;
+			flex-wrap: wrap;
+			gap: 12px;
+
+			&:last-child {
+				flex: 1 0 auto;
+
+				>div {
+					flex-grow: 1;
+				}
+
+				>section {
+					// MAGIC: Prevent div above from growing unless wrapped to its own line
+					flex-grow: 9999;
+					align-items: end;
+					display: flex;
+					gap: 4px;
+
+					>.input {
+						flex: 1 1 auto;
+					}
+				}
+			}
+		}
+	}
+}
+</style>
diff --git a/packages/frontend/src/components/MkPostForm.vue b/packages/frontend/src/components/MkPostForm.vue
index 42a3748d9a..16db1f0e20 100644
--- a/packages/frontend/src/components/MkPostForm.vue
+++ b/packages/frontend/src/components/MkPostForm.vue
@@ -49,6 +49,7 @@
 	<MkNoteSimple v-if="reply" :class="$style.targetNote" :note="reply"/>
 	<MkNoteSimple v-if="renote" :class="$style.targetNote" :note="renote"/>
 	<div v-if="quoteId" :class="$style.withQuote"><i class="ti ti-quote"></i> {{ i18n.ts.quoteAttached }}<button @click="quoteId = null"><i class="ti ti-x"></i></button></div>
+	<MkEventEditor v-if="event" v-model="event" @destroyed="event = null"/>
 	<div v-if="visibility === 'specified'" :class="$style.toSpecified">
 		<span style="margin-right: 8px;">{{ i18n.ts.recipient }}</span>
 		<div :class="$style.visibleUsers">
@@ -75,6 +76,7 @@
 		<div :class="$style.footerLeft">
 			<button v-tooltip="i18n.ts.attachFile" class="_button" :class="$style.footerButton" @click="chooseFileFrom"><i class="ti ti-photo-plus"></i></button>
 			<button v-tooltip="i18n.ts.poll" class="_button" :class="[$style.footerButton, { [$style.footerButtonActive]: poll }]" @click="togglePoll"><i class="ti ti-chart-arrows"></i></button>
+			<button v-tooltip="i18n.ts.event" class="_button" :class="[$style.footerButton, { [$style.footerButtonActive]: event }]" @click="toggleEvent"><i class="ti ti-calendar"></i></button>
 			<button v-tooltip="i18n.ts.useCw" class="_button" :class="[$style.footerButton, { [$style.footerButtonActive]: useCw }]" @click="useCw = !useCw"><i class="ti ti-eye-off"></i></button>
 			<button v-tooltip="i18n.ts.mention" class="_button" :class="$style.footerButton" @click="insertMention"><i class="ti ti-at"></i></button>
 			<button v-tooltip="i18n.ts.hashtags" class="_button" :class="[$style.footerButton, { [$style.footerButtonActive]: withHashtags }]" @click="withHashtags = !withHashtags"><i class="ti ti-hash"></i></button>
@@ -103,6 +105,7 @@ import MkNoteSimple from '@/components/MkNoteSimple.vue';
 import MkNotePreview from '@/components/MkNotePreview.vue';
 import XPostFormAttaches from '@/components/MkPostFormAttaches.vue';
 import MkPollEditor from '@/components/MkPollEditor.vue';
+import MkEventEditor from '@/components/MkEventEditor.vue';
 import { host, url } from '@/config';
 import { erase, unique } from '@/scripts/array';
 import { extractMentions } from '@/scripts/extract-mentions';
@@ -165,6 +168,12 @@ let poll = $ref<{
 	expiresAt: string | null;
 	expiredAfter: string | null;
 } | null>(null);
+let event = $ref<{
+	title: string;
+	start: string;
+	end: string | null;
+	metadata: Record<string, string>;
+} | null>(null);
 let useCw = $ref(false);
 let showPreview = $ref(false);
 let cw = $ref<string | null>(null);
@@ -235,7 +244,7 @@ const maxTextLength = $computed((): number => {
 
 const canPost = $computed((): boolean => {
 	return !posting && !posted &&
-		(1 <= textLength || 1 <= files.length || !!poll || !!props.renote) &&
+		(1 <= textLength || 1 <= files.length || !!poll || !!props.renote || !!event) &&
 		(textLength <= maxTextLength) &&
 		(!poll || poll.choices.length >= 2);
 });
@@ -331,6 +340,7 @@ function watchForDraft() {
 	watch($$(useCw), () => saveDraft());
 	watch($$(cw), () => saveDraft());
 	watch($$(poll), () => saveDraft());
+	watch($$(event), () => saveDraft());
 	watch($$(files), () => saveDraft(), { deep: true });
 	watch($$(visibility), () => saveDraft());
 	watch($$(localOnly), () => saveDraft());
@@ -375,6 +385,19 @@ function togglePoll() {
 	}
 }
 
+function toggleEvent() {
+	if (event) {
+		event = null;
+	} else {
+		event = {
+			title: '',
+			start: (new Date()).toString(),
+			end: null,
+			metadata: {},
+		};
+	}
+}
+
 function addTag(tag: string) {
 	insertTextAtCursor(textareaEl, ` #${tag} `);
 }
@@ -513,6 +536,7 @@ function clear() {
 	text = '';
 	files = [];
 	poll = null;
+	event = null;
 	quoteId = null;
 }
 
@@ -626,6 +650,7 @@ function saveDraft() {
 			localOnly: localOnly,
 			files: files,
 			poll: poll,
+			event: event,
 		},
 	};
 
@@ -687,6 +712,7 @@ async function post(ev?: MouseEvent) {
 		renoteId: props.renote ? props.renote.id : quoteId ? quoteId : undefined,
 		channelId: props.channel ? props.channel.id : undefined,
 		poll: poll,
+		event: event,
 		cw: useCw ? cw ?? '' : undefined,
 		localOnly: localOnly,
 		visibility: visibility,
@@ -847,6 +873,9 @@ onMounted(() => {
 				if (draft.data.poll) {
 					poll = draft.data.poll;
 				}
+				if (draft.data.event) {
+					event = draft.data.event;
+				}
 			}
 		}
 
@@ -865,6 +894,14 @@ onMounted(() => {
 					expiredAfter: init.poll.expiredAfter,
 				};
 			}
+			if (init.event) {
+				event = {
+					title: init.event.title,
+					start: init.event.start,
+					end: init.event.end,
+					metadata: init.event.metadata,
+				};
+			}
 			visibility = init.visibility;
 			localOnly = init.localOnly;
 			quoteId = init.renote ? init.renote.id : null;