diff --git a/public/js/main.js b/public/js/main.js
index bedf6cb..59e826e 100644
--- a/public/js/main.js
+++ b/public/js/main.js
@@ -1477,9 +1477,16 @@ async function calculatePreviousBalance() {
     return 0;
   }
   
+  // Filter out entries with invalid dates
+  const validEntries = allEntries.filter(e => e.date && e.date.match(/^\d{4}-\d{2}-\d{2}$/));
+  
+  if (validEntries.length === 0) {
+    return 0;
+  }
+  
   // Find earliest date
-  const earliestDate = allEntries.reduce((earliest, entry) => {
-    const entryDate = new Date(entry.date);
+  const earliestDate = validEntries.reduce((earliest, entry) => {
+    const entryDate = new Date(entry.date + 'T00:00:00');
     return !earliest || entryDate < earliest ? entryDate : earliest;
   }, null);
   
@@ -1496,6 +1503,9 @@ async function calculatePreviousBalance() {
   let checkMonth = firstMonth;
   
   const today = new Date();
+  today.setHours(0, 0, 0, 0); // Normalize to start of day
+  
+  console.log(`calculatePreviousBalance: Calculating from ${firstYear}-${firstMonth+1} to ${currentYear}-${currentMonth} (exclusive)`);
   
   // Loop through all months from first entry until previous month of displayed month
   while (checkYear < currentYear || (checkYear === currentYear && checkMonth < currentMonth)) {
@@ -1505,9 +1515,9 @@ async function calculatePreviousBalance() {
     
     const entries = await fetchEntries(firstDay, lastDayStr);
     
-    // For past months, use full month. For current month (if displayed), limit to today
-    const monthEnd = new Date(checkYear, checkMonth + 1, 0);
-    const limitDate = monthEnd;  // Always use full month for previous balance calculation
+    // For past months (completed months), count ALL workdays
+    // Only limit to today if this is the current calendar month
+    const isCurrentCalendarMonth = (checkYear === today.getFullYear() && checkMonth === today.getMonth());
     
     let workdaysPassed = 0;
     const monthLastDay = new Date(checkYear, checkMonth + 1, 0).getDate();
@@ -1526,8 +1536,16 @@ async function calculatePreviousBalance() {
         .map(e => e.date)
     );
     
+    // Count workdays (all days for past months, up to today for current month)
     for (let day = 1; day <= monthLastDay; day++) {
       const dateObj = new Date(checkYear, checkMonth, day);
+      dateObj.setHours(0, 0, 0, 0);
+      
+      // For current calendar month, only count up to today
+      if (isCurrentCalendarMonth && dateObj > today) {
+        break;
+      }
+      
       const year = dateObj.getFullYear();
       const month = String(dateObj.getMonth() + 1).padStart(2, '0');
       const dayStr = String(dateObj.getDate()).padStart(2, '0');
@@ -1548,6 +1566,8 @@ async function calculatePreviousBalance() {
     const actualHours = entries.reduce((sum, entry) => sum + entry.netHours, 0);
     const monthBalance = actualHours - targetHours;
     
+    console.log(`Month ${checkYear}-${String(checkMonth+1).padStart(2, '0')}: ${entries.length} entries, ${workdaysPassed} workdays, ${actualHours.toFixed(1)}h actual, ${targetHours.toFixed(1)}h target, balance: ${monthBalance.toFixed(1)}h`);
+    
     totalBalance += monthBalance;
     
     // Move to next month
@@ -1558,6 +1578,7 @@ async function calculatePreviousBalance() {
     }
   }
   
+  console.log(`Total previous balance: ${totalBalance.toFixed(1)}h`);
   return totalBalance;
 }