Set fixed date in widget_gallery test

crates/egui_demo_lib/src/demo/demo_app_windows.rs

@@ -394,11 +394,17 @@ mod tests {
         let mut errors = Vec::new();
 
         for mut demo in demos.demos {
+            // Remove the emoji from the demo name
             let name = demo
                 .name()
                 .split_once(' ')
                 .map_or(demo.name(), |(_, name)| name);
 
+            // Widget Gallery needs to be customized (to set a specific date) and has its own test
+            if name == "Widget Gallery" {
+                continue;
+            }
+
             let mut harness = Harness::new(|ctx| {
                 demo.show(ctx, &mut true);
             });

crates/egui_demo_lib/src/demo/widget_gallery.rs

@@ -297,7 +297,11 @@ mod tests {
 
     #[test]
     pub fn should_match_screenshot() {
-        let mut demo = WidgetGallery::default();
+        let mut demo = WidgetGallery {
+            // If we don't set a fixed date, the snapshot test will fail.
+            date: Some(chrono::NaiveDate::from_ymd_opt(2024, 1, 1).unwrap()),
+            ..Default::default()
+        };
         let app = |ctx: &Context| {
             CentralPanel::default().show(ctx, |ui| {
                 demo.ui(ui);