diff --git a/templates/index.html b/templates/index.html
index 954e69a..831fe2f 100644
--- a/templates/index.html
+++ b/templates/index.html
@@ -126,7 +126,20 @@
     });
 
     function setDefaultDate() {
-        document.getElementById('dateInput').value = new Date().toISOString().split('T')[0];
+        // Use local date format YYYY-MM-DD
+        const today = new Date();
+        const year = today.getFullYear();
+        const month = String(today.getMonth() + 1).padStart(2, '0');
+        const day = String(today.getDate()).padStart(2, '0');
+        document.getElementById('dateInput').value = `${year}-${month}-${day}`;
+    }
+
+    // Helper function to format date as YYYY-MM-DD in local timezone
+    function formatDateLocal(date) {
+        const year = date.getFullYear();
+        const month = String(date.getMonth() + 1).padStart(2, '0');
+        const day = String(date.getDate()).padStart(2, '0');
+        return `${year}-${month}-${day}`;
     }
 
     async function loadTasks() {
@@ -244,7 +257,7 @@
         const today = new Date();
         const day = today.getDay();
         const diff = today.getDate() - day + (day === 0 ? -6 : 1) + (offset * 7);
-        const monday = new Date(today.setDate(diff));
+        const monday = new Date(today.getFullYear(), today.getMonth(), diff);
         monday.setHours(0, 0, 0, 0);
         return monday;
     }
@@ -258,8 +271,11 @@
         document.getElementById('weekLabel').textContent = 
             `${weekStart.toLocaleDateString('en-AU', options)} - ${weekEnd.toLocaleDateString('en-AU', options)}, ${weekEnd.getFullYear()}`;
         
+        // Use local date format (YYYY-MM-DD) instead of toISOString() to avoid timezone issues
+        const weekStartStr = formatDateLocal(weekStart);
+        
         try {
-            const response = await fetch(`/api/weekly-summary?week_start=${weekStart.toISOString()}`);
+            const response = await fetch(`/api/weekly-summary?week_start=${weekStartStr}`);
             const data = await response.json();
             renderWeeklySummary(data);
         } catch (error) {
@@ -328,7 +344,9 @@
         
         let html = '';
         entries.slice(0, 20).forEach(entry => {
-            const date = new Date(entry.date);
+            // Parse date as local date (add T00:00:00 to treat as local, not UTC)
+            const dateParts = entry.date.split('-');
+            const date = new Date(dateParts[0], dateParts[1] - 1, dateParts[2]);
             const dateStr = date.toLocaleDateString('en-AU', { weekday: 'short', month: 'short', day: 'numeric' });
             
             html += `<div class="entry-item" data-id="${entry.id}">
@@ -371,8 +389,8 @@
         
         const data = window.currentWeekData;
         const days = ['Monday', 'Tuesday', 'Wednesday', 'Thursday', 'Friday', 'Saturday', 'Sunday'];
-        const weekStart = new Date(data.week_start);
-        const weekEnd = new Date(data.week_end);
+        const weekStart = new Date(data.week_start + 'T00:00:00');
+        const weekEnd = new Date(data.week_end + 'T00:00:00');
         const options = { year: 'numeric', month: 'long', day: 'numeric' };
         
         document.getElementById('printPeriod').textContent =