diff --git a/assets/main.css b/assets/main.css
index f449903..5e50106 100644
--- a/assets/main.css
+++ b/assets/main.css
@@ -215,15 +215,25 @@ ul#server_selection_list {
 	margin-bottom: 0.5em;
 }
 
+.date_separator {
+	font-weight: bold;
+	margin-top: 0.3em;
+	font-size: 75%;
+	text-align: center;
+	color: #555;
+	border-top: 1px solid #ccc;
+}
+
 .post {
-	padding: 0.1em;
-	margin: 0.6em 0 0.2em;
+	padding: 0.2em;
+	margin-top: 0.3em;
 	display: grid;
-	grid-template-rows: auto auto;
+	grid-template-rows: auto auto auto;
 	grid-template-columns: auto auto;
+	min-height: 3ex;
 }
 .post.same_author {
-	margin-top: 0.2em;
+	margin-top: 0;
 }
 .post:first-child {
 	margin-top: 8px;
@@ -234,6 +244,9 @@ ul#server_selection_list {
 .post:hover {
 	background-color: #e4e4e4;
 }
+.post:not(.show_time) {
+	position: relative;
+}
 
 .post .author {
 	grid-row: 1;
@@ -242,7 +255,7 @@ ul#server_selection_list {
 	font-weight: bold;
 	align-self: end;
 }
-.post.same_author .author {
+.post.same_author:not(.show_time) .author {
 	display: none;
 }
 
@@ -254,8 +267,16 @@ ul#server_selection_list {
 	color: #888;
 	align-self: end;
 }
-.post.same_author .create_at {
+.post:not(.show_time) .create_at {
 	display: none;
+	position: absolute;
+	background-color: #e4e4e4;
+	padding: 0 0.2em;
+	right: 0;
+	top: 0;
+}
+.post:not(.show_time):hover .create_at {
+	display: block;
 }
 
 .post .message {
@@ -264,8 +285,15 @@ ul#server_selection_list {
 	grid-column-start: 1;
 	grid-column-end: 3;
 }
+.post.special .message {
+	color: #555;
+	font-size: 75%;
+}
 
 .post ul.attachments {
+	grid-row: 3;
+	grid-column-start: 1;
+	grid-column-end: 3;
 	margin: 0;
 	padding: 0;
 	list-style: none;
diff --git a/js/util.js b/js/util.js
index 1697ba9..2c7aaf0 100644
--- a/js/util.js
+++ b/js/util.js
@@ -90,8 +90,9 @@ function toTimeZone(date, timezoneString) {
 	return new Date(date.toLocaleString("en-US", {timeZone: timezoneString}));
 }
 
-function formatDdddMmYy(date) {
-	return `${date.getFullYear()}-${padLeft(date.getMonth() + 1, 2, "0")}-${padLeft(date.getDate(), 2, "0")}`;
+function formatYyyyMmDdWeekday(date) {
+	const weekday = ["Su", "Mo", "Tu", "We", "Th", "Fr", "Sa"][date.getDay()];
+	return `${date.getFullYear()}-${padLeft(date.getMonth() + 1, 2, "0")}-${padLeft(date.getDate(), 2, "0")}, ${weekday}`;
 }
 
 function formatHhMm(date) {
diff --git a/js/view/messages.js b/js/view/messages.js
index e52842d..87f1635 100644
--- a/js/view/messages.js
+++ b/js/view/messages.js
@@ -8,25 +8,63 @@ function transformMessageText(message) {
 }
 
 
+function shouldShowTime(lastShownTime, time) {
+	const sim = dateSimilarity(lastShownTime, time);
+	if (sim < DATE_SIMILARITY.date) {
+		return {date: true, time: true};
+	}
+	const minutesSinceLastShown = (time - lastShownTime) / 1000 / 60;
+	if (minutesSinceLastShown >= 15) {
+		return {date: false, time: true};
+	}
+	return {date: false, time: false};
+}
+
+
 async function createMessageElement(client, post, lastTime, lastAuthor) {
+	let nodes = [];
+
 	const users = await client.getUsers();
 	const isThreadReply = !!post.parent_id;
 
+	const createAt = new Date(post.create_at);
+	let createAtLocalized = createAt;
+	let lastTimeLocalized = lastTime;
+	try {
+		if (client.me.timezone.useAutomaticTimezone !== "true") {
+			createAtLocalized = toTimeZone(createAt, client.me.timezone.manualTimezone);
+			lastTimeLocalized = toTimeZone(lastTime, client.me.timezone.manualTimezone);
+		}
+	} catch(e) {}
+	const showTime = shouldShowTime(lastTimeLocalized, createAtLocalized);
+	if (showTime.time) {
+		lastTime = createAt;
+	}
+
+	const postDiv = document.createElement("div");
+	postDiv.className = "post";
+	if (post.type !== "") {
+		postDiv.className += " special";
+	}
+
+	if (showTime.date) {
+		const dateElement = document.createElement("div");
+		dateElement.className = "date_separator";
+		dateElement.innerText = formatYyyyMmDdWeekday(createAtLocalized);
+		nodes.push(dateElement);
+	}
+
+	if (showTime.time) {
+		postDiv.className += " show_time";
+	}
+
 	const messageDiv = document.createElement("div");
 	messageDiv.className = "message";
 	messageDiv.innerText = transformMessageText(post.message);
 
-	let createAt = new Date(post.create_at);
-	if (client.me.timezone.useAutomaticTimezone !== "true") {
-		createAt = toTimeZone(createAt, client.me.timezone.manualTimezone);
-	}
 	const createAtDiv = document.createElement("time");
 	createAtDiv.className = "create_at";
-	const sim = dateSimilarity(lastTime, createAt);
-	lastTime = createAt;
-	let createAtText = "";
-	if (sim < DATE_SIMILARITY.date) createAtText += formatDdddMmYy(createAt);
-	if (sim < DATE_SIMILARITY.minutes) createAtText += " " + formatHhMm(createAt);
+	let createAtText = formatHhMm(createAtLocalized);
 	createAtDiv.title = createAt.toString();
 	createAtDiv.innerText = createAtText;
 	createAtDiv.dateTime = createAt.toISOString();
@@ -36,8 +74,6 @@ async function createMessageElement(client, post, lastTime, lastAuthor) {
 	authorDiv.className = "author";
 	authorDiv.innerText = authorName;
 
-	const postDiv = document.createElement("div");
-	postDiv.className = "post";
 	if (lastAuthor === post.user_id) {
 		postDiv.className += " same_author";
 	}
@@ -72,7 +108,9 @@ async function createMessageElement(client, post, lastTime, lastAuthor) {
 		postDiv.appendChild(attachmentsUl);
 	}
 
-	return {postDiv, lastTime, lastAuthor};
+	nodes.push(postDiv);
+
+	return {nodes, lastTime, lastAuthor};
 }
 
 
@@ -84,7 +122,7 @@ async function populateChannelContents(client, channel, contents) {
 	let nodes = [];
 	for (let id of contents.order) {
 		result = await createMessageElement(client, contents.posts[id], result.lastTime, result.lastAuthor);
-		nodes.push(result.postDiv);
+		nodes.push(...result.nodes);
 	}
 
 	byId("channel_contents").dataset["server"] = client.endpoint;
@@ -106,7 +144,7 @@ async function addMessage(client, post) {
 	);
 	byId("channel_contents").dataset["lastTime"] = result.lastTime.getTime();
 	byId("channel_contents").dataset["lastAuthor"] = result.lastAuthor;
-	byId("channel_contents").appendChild(result.postDiv);
+	byId("channel_contents").append(...result.nodes);
 
 	if (shouldScroll) {
 		scrollToBottom();