diff --git a/src/templates/mapping.go b/src/templates/mapping.go
index 7dc9c7f3..69140b16 100644
--- a/src/templates/mapping.go
+++ b/src/templates/mapping.go
@@ -12,6 +12,7 @@ import (
 	"git.handmade.network/hmn/hmn/src/hmnurl"
 	"git.handmade.network/hmn/hmn/src/links"
 	"git.handmade.network/hmn/hmn/src/models"
+	"git.handmade.network/hmn/hmn/src/utils"
 )
 
 func PostToTemplate(p *models.Post, author *models.User) Post {
@@ -494,6 +495,17 @@ func CalendarEventToTemplate(ev *calendar.CalendarEvent) CalendarEvent {
 	}
 }
 
+func JamToBannerEvent(jam hmndata.Jam) BannerEvent {
+	return BannerEvent{
+		Slug:           jam.Slug,
+		DaysUntilStart: utils.DaysUntil(jam.StartTime),
+		DaysUntilEnd:   utils.DaysUntil(jam.EndTime),
+		StartTimeUnix:  jam.StartTime.Unix(),
+		EndTimeUnix:    jam.EndTime.Unix(),
+		Url:            hmnurl.BuildJamIndexAny(jam.UrlSlug),
+	}
+}
+
 func maybeString(s *string) string {
 	if s == nil {
 		return ""
diff --git a/src/templates/src/include/header-2024.html b/src/templates/src/include/header-2024.html
index a92ab908..d94fb2cc 100644
--- a/src/templates/src/include/header-2024.html
+++ b/src/templates/src/include/header-2024.html
@@ -56,6 +56,32 @@
         {{ end }}
     </div>
 </header>
+{{ if and .Header.BannerEvent (not .Header.SuppressBanners) }}
+    {{ with .Header.BannerEvent }}
+        {{ if eq .Slug "VJ2024" }}
+            <a
+                class="db tc pv2 link-normal c-white"
+                style="background: linear-gradient(to bottom right, #20dddd, #007178)"
+                href="{{ .Url }}"
+            >
+                <b>Visibility Jam.</b>
+                July 19-21, 2024.
+                {{ if gt .DaysUntilEnd 0 }}
+                    {{ if eq .DaysUntilStart 0 }}
+                        <b>Happening now.</b>
+                    {{ else if eq .DaysUntilStart 1 }}
+                        <b>Starting tomorrow.</b>
+                    {{ else }}
+                        <b>In {{ .DaysUntilStart }} days.</b>
+                    {{ end }}
+                {{ else }}
+                    <b>See the results.</b>
+                {{ end }}
+            </a>
+        {{ end }}
+    {{ end }}
+{{ end }}
+
 <script type="text/javascript">
     document.addEventListener("DOMContentLoaded", function() {
         const header = document.querySelector('#site-header');
diff --git a/src/templates/src/layouts/base-2024.html b/src/templates/src/layouts/base-2024.html
index f04b5fdf..af631ecd 100644
--- a/src/templates/src/layouts/base-2024.html
+++ b/src/templates/src/layouts/base-2024.html
@@ -66,7 +66,7 @@
         {{ block "content-top" . }}{{ end }}
     </div>
     <!-- TODO: Notices -->
-	<div class="c-white flex-grow-1">
+	<div class="flex-grow-1">
 		{{ block "content" . }}{{ end }}
 	</div>
     {{ template "footer-2024.html" . }}
diff --git a/src/templates/types.go b/src/templates/types.go
index 5e1d510e..bbf67cf1 100644
--- a/src/templates/types.go
+++ b/src/templates/types.go
@@ -60,6 +60,17 @@ type Header struct {
 	AboutUrl        string
 
 	Project *ProjectHeader
+
+	BannerEvent     *BannerEvent
+	SuppressBanners bool
+}
+
+type BannerEvent struct {
+	Slug string
+	Url  string
+
+	DaysUntilStart, DaysUntilEnd int
+	StartTimeUnix, EndTimeUnix   int64
 }
 
 type ProjectHeader struct {
diff --git a/src/utils/utils.go b/src/utils/utils.go
index 0debafd5..7d5add95 100644
--- a/src/utils/utils.go
+++ b/src/utils/utils.go
@@ -68,6 +68,14 @@ func NumPages(numThings, thingsPerPage int) int {
 	return Max(int(math.Ceil(float64(numThings)/float64(thingsPerPage))), 1)
 }
 
+func DaysUntil(t time.Time) int {
+	d := t.Sub(time.Now())
+	if d < 0 {
+		d = 0
+	}
+	return int(DurationRoundUp(d, 24*time.Hour) / (24 * time.Hour))
+}
+
 /*
 Recover a panic and convert it to a returned error. Call it like so:
 
diff --git a/src/website/base_data.go b/src/website/base_data.go
index e6858811..2fe97c3d 100644
--- a/src/website/base_data.go
+++ b/src/website/base_data.go
@@ -1,11 +1,15 @@
 package website
 
 import (
+	"time"
+
 	"git.handmade.network/hmn/hmn/src/buildscss"
 	"git.handmade.network/hmn/hmn/src/config"
+	"git.handmade.network/hmn/hmn/src/hmndata"
 	"git.handmade.network/hmn/hmn/src/hmnurl"
 	"git.handmade.network/hmn/hmn/src/models"
 	"git.handmade.network/hmn/hmn/src/templates"
+	"git.handmade.network/hmn/hmn/src/utils"
 )
 
 func getBaseDataAutocrumb(c *RequestContext, title string) templates.BaseData {
@@ -43,6 +47,19 @@ func getBaseData(c *RequestContext, title string, breadcrumbs []templates.Breadc
 		}
 	}
 
+	var bannerEvent *templates.BannerEvent
+	for _, jam := range hmndata.AllJams {
+		graceBefore := (24 * time.Hour) * 30
+		graceAfter := (24 * time.Hour) * 14
+
+		afterStart := time.Now().After(jam.StartTime.Add(-graceBefore))
+		beforeEnd := time.Now().Before(jam.EndTime.Add(graceAfter))
+
+		if afterStart && beforeEnd {
+			bannerEvent = utils.P(templates.JamToBannerEvent(jam))
+		}
+	}
+
 	baseData := templates.BaseData{
 		Title:       title,
 		Breadcrumbs: breadcrumbs,
@@ -81,6 +98,8 @@ func getBaseData(c *RequestContext, title string, breadcrumbs []templates.Breadc
 			CalendarUrl:     hmnurl.BuildCalendarIndex(),
 			ManifestoUrl:    hmnurl.BuildManifesto(),
 			AboutUrl:        hmnurl.BuildAbout(),
+
+			BannerEvent: bannerEvent,
 		},
 		Footer: templates.Footer{
 			HomepageUrl:                hmnurl.BuildHomepage(),
diff --git a/src/website/jam.go b/src/website/jam.go
index 44dec1cd..7e418c73 100644
--- a/src/website/jam.go
+++ b/src/website/jam.go
@@ -110,6 +110,7 @@ func JamIndex2024_Visibility(c *RequestContext) ResponseData {
 		{Name: "twitter:image", Value: hmnurl.BuildPublic("visjam2024/TwitterCard.png", true)},
 	}
 	baseData.BodyClasses = append(baseData.BodyClasses, "header-transparent")
+	baseData.Header.SuppressBanners = true
 
 	type JamPageData struct {
 		templates.BaseData
@@ -157,8 +158,8 @@ func getVJ2024BaseData(c *RequestContext) (JamBaseDataVJ2024, error) {
 	}
 
 	return JamBaseDataVJ2024{
-		DaysUntilStart: daysUntil(jam.StartTime),
-		DaysUntilEnd:   daysUntil(jam.EndTime),
+		DaysUntilStart: utils.DaysUntil(jam.StartTime),
+		DaysUntilEnd:   utils.DaysUntil(jam.EndTime),
 		StartTimeUnix:  jam.StartTime.Unix(),
 		EndTimeUnix:    jam.EndTime.Unix(),
 
@@ -301,8 +302,8 @@ type JamFeedDataLJ2024 struct {
 }
 
 func getLJ2024BaseData(c *RequestContext) (JamBaseDataLJ2024, error) {
-	daysUntilStart := daysUntil(hmndata.LJ2024.StartTime)
-	daysUntilEnd := daysUntil(hmndata.LJ2024.EndTime)
+	daysUntilStart := utils.DaysUntil(hmndata.LJ2024.StartTime)
+	daysUntilEnd := utils.DaysUntil(hmndata.LJ2024.EndTime)
 
 	tmpl := JamBaseDataLJ2024{
 		UserAvatarUrl:  templates.UserAvatarDefaultUrl("dark"),
@@ -405,8 +406,8 @@ func getTwitchEmbedUrl(c *RequestContext) string {
 func JamIndex2023(c *RequestContext) ResponseData {
 	var res ResponseData
 
-	daysUntilStart := daysUntil(hmndata.WRJ2023.StartTime)
-	daysUntilEnd := daysUntil(hmndata.WRJ2023.EndTime)
+	daysUntilStart := utils.DaysUntil(hmndata.WRJ2023.StartTime)
+	daysUntilEnd := utils.DaysUntil(hmndata.WRJ2023.EndTime)
 
 	baseData := getBaseDataAutocrumb(c, hmndata.WRJ2023.Name)
 	baseData.OpenGraphItems = []templates.OpenGraphItem{
@@ -561,8 +562,8 @@ func JamFeed2023(c *RequestContext) ResponseData {
 		TimelineItems []templates.TimelineItem
 	}
 
-	daysUntilStart := daysUntil(hmndata.WRJ2023.StartTime)
-	daysUntilEnd := daysUntil(hmndata.WRJ2023.EndTime)
+	daysUntilStart := utils.DaysUntil(hmndata.WRJ2023.StartTime)
+	daysUntilEnd := utils.DaysUntil(hmndata.WRJ2023.EndTime)
 
 	baseData := getBaseDataAutocrumb(c, hmndata.WRJ2023.Name)
 	baseData.OpenGraphItems = []templates.OpenGraphItem{
@@ -587,8 +588,8 @@ func JamFeed2023(c *RequestContext) ResponseData {
 func JamIndex2023_Visibility(c *RequestContext) ResponseData {
 	var res ResponseData
 
-	daysUntilStart := daysUntil(hmndata.VJ2023.StartTime)
-	daysUntilEnd := daysUntil(hmndata.VJ2023.EndTime)
+	daysUntilStart := utils.DaysUntil(hmndata.VJ2023.StartTime)
+	daysUntilEnd := utils.DaysUntil(hmndata.VJ2023.EndTime)
 
 	baseData := getBaseDataAutocrumb(c, hmndata.VJ2023.Name)
 	baseData.OpenGraphItems = []templates.OpenGraphItem{
@@ -729,8 +730,8 @@ func JamFeed2023_Visibility(c *RequestContext) ResponseData {
 		TimelineItems []templates.TimelineItem
 	}
 
-	daysUntilStart := daysUntil(hmndata.VJ2023.StartTime)
-	daysUntilEnd := daysUntil(hmndata.VJ2023.EndTime)
+	daysUntilStart := utils.DaysUntil(hmndata.VJ2023.StartTime)
+	daysUntilEnd := utils.DaysUntil(hmndata.VJ2023.EndTime)
 
 	baseData := getBaseDataAutocrumb(c, hmndata.VJ2023.Name)
 
@@ -804,8 +805,8 @@ func JamRecap2023_Visibility(c *RequestContext) ResponseData {
 func JamIndex2022(c *RequestContext) ResponseData {
 	var res ResponseData
 
-	daysUntilStart := daysUntil(hmndata.WRJ2022.StartTime)
-	daysUntilEnd := daysUntil(hmndata.WRJ2022.EndTime)
+	daysUntilStart := utils.DaysUntil(hmndata.WRJ2022.StartTime)
+	daysUntilEnd := utils.DaysUntil(hmndata.WRJ2022.EndTime)
 
 	baseData := getBaseDataAutocrumb(c, hmndata.WRJ2022.Name)
 	baseData.OpenGraphItems = []templates.OpenGraphItem{
@@ -940,8 +941,8 @@ func JamFeed2022(c *RequestContext) ResponseData {
 		TimelineItems []templates.TimelineItem
 	}
 
-	daysUntilStart := daysUntil(hmndata.WRJ2022.StartTime)
-	daysUntilEnd := daysUntil(hmndata.WRJ2022.EndTime)
+	daysUntilStart := utils.DaysUntil(hmndata.WRJ2022.StartTime)
+	daysUntilEnd := utils.DaysUntil(hmndata.WRJ2022.EndTime)
 
 	baseData := getBaseDataAutocrumb(c, hmndata.WRJ2022.Name)
 	baseData.OpenGraphItems = []templates.OpenGraphItem{
@@ -966,7 +967,7 @@ func JamFeed2022(c *RequestContext) ResponseData {
 func JamIndex2021(c *RequestContext) ResponseData {
 	var res ResponseData
 
-	daysUntilJam := daysUntil(hmndata.WRJ2021.StartTime)
+	daysUntilJam := utils.DaysUntil(hmndata.WRJ2021.StartTime)
 	if daysUntilJam < 0 {
 		daysUntilJam = 0
 	}
@@ -1022,11 +1023,3 @@ func JamIndex2021(c *RequestContext) ResponseData {
 	}, c.Perf)
 	return res
 }
-
-func daysUntil(t time.Time) int {
-	d := t.Sub(time.Now())
-	if d < 0 {
-		d = 0
-	}
-	return int(utils.DurationRoundUp(d, 24*time.Hour) / (24 * time.Hour))
-}
diff --git a/src/website/landing.go b/src/website/landing.go
index 4449b57d..d5b5750a 100644
--- a/src/website/landing.go
+++ b/src/website/landing.go
@@ -9,6 +9,7 @@ import (
 	"git.handmade.network/hmn/hmn/src/models"
 	"git.handmade.network/hmn/hmn/src/oops"
 	"git.handmade.network/hmn/hmn/src/templates"
+	"git.handmade.network/hmn/hmn/src/utils"
 )
 
 func Index(c *RequestContext) ResponseData {
@@ -149,14 +150,14 @@ func Index(c *RequestContext) ResponseData {
 		NewProjectUrl:  hmnurl.BuildProjectNew(),
 
 		JamUrl:            hmnurl.BuildJamIndex2024_Learning(),
-		JamDaysUntilStart: daysUntil(hmndata.LJ2024.StartTime),
-		JamDaysUntilEnd:   daysUntil(hmndata.LJ2024.EndTime),
+		JamDaysUntilStart: utils.DaysUntil(hmndata.LJ2024.StartTime),
+		JamDaysUntilEnd:   utils.DaysUntil(hmndata.LJ2024.EndTime),
 
-		HMSDaysUntilStart: daysUntil(hmndata.HMS2024.StartTime),
-		HMSDaysUntilEnd:   daysUntil(hmndata.HMS2024.EndTime),
+		HMSDaysUntilStart: utils.DaysUntil(hmndata.HMS2024.StartTime),
+		HMSDaysUntilEnd:   utils.DaysUntil(hmndata.HMS2024.EndTime),
 
-		HMBostonDaysUntilStart: daysUntil(hmndata.HMBoston2024.StartTime),
-		HMBostonDaysUntilEnd:   daysUntil(hmndata.HMBoston2024.EndTime),
+		HMBostonDaysUntilStart: utils.DaysUntil(hmndata.HMBoston2024.StartTime),
+		HMBostonDaysUntilEnd:   utils.DaysUntil(hmndata.HMBoston2024.EndTime),
 	}, c.Perf)
 	if err != nil {
 		return c.ErrorResponse(http.StatusInternalServerError, oops.New(err, "failed to render landing page template"))