diff --git a/LICENSE b/LICENSE
index e13fb3a..792a64f 100644
--- a/LICENSE
+++ b/LICENSE
@@ -1,5 +1,5 @@
     AdventureLog: Self-hostable travel tracker and trip planner.
-    Copyright (C) 2024  Sean Morley
+    Copyright (C) 2023-2025  Sean Morley
     Contact: contact@seanmorley.com
 
     This program is free software: you can redistribute it and/or modify
diff --git a/frontend/src/lib/components/CollectionModal.svelte b/frontend/src/lib/components/CollectionModal.svelte
index 5c134e0..9f1acf9 100644
--- a/frontend/src/lib/components/CollectionModal.svelte
+++ b/frontend/src/lib/components/CollectionModal.svelte
@@ -51,6 +51,19 @@
 			collection.end_date = collection.start_date;
 		}
 
+		if (
+			collection.start_date &&
+			collection.end_date &&
+			collection.start_date > collection.end_date
+		) {
+			addToast('error', $t('adventures.start_before_end_error'));
+			return;
+		}
+
+		if (!collection.start_date && collection.end_date) {
+			collection.start_date = collection.end_date;
+		}
+
 		if (collection.id === '') {
 			let res = await fetch('/api/collections', {
 				method: 'POST',