diff --git a/.eleventy.js b/.eleventy.js
index fa65db0..545b68f 100644
--- a/.eleventy.js
+++ b/.eleventy.js
@@ -15,7 +15,7 @@ module.exports = function(eleventyConfig) {
 
   // https://html.spec.whatwg.org/multipage/common-microsyntaxes.html#valid-date-string
   eleventyConfig.addFilter('htmlDateString', (dateObj) => {
-    return DateTime.fromJSDate(dateObj).toFormat('yyyy-LL-dd');
+    return DateTime.fromJSDate(dateObj, {zone: 'utc'}).toFormat('yyyy-LL-dd');
   });
 
   // Get the first `n` elements of a collection.