diff --git a/frontend/src/components/sidebar/SidebarStatsBar.tsx b/frontend/src/components/sidebar/SidebarStatsBar.tsx
index 64d78f0e..eb54d92c 100644
--- a/frontend/src/components/sidebar/SidebarStatsBar.tsx
+++ b/frontend/src/components/sidebar/SidebarStatsBar.tsx
@@ -18,19 +18,21 @@ function formatDuration(totalSeconds: number): string {
   return m > 0 ? `${h}h ${m}m` : `${h}h`
 }
 
+function parseUTCTimestamp(st: string): number {
+  // Backend returns naive UTC timestamps without 'Z' suffix.
+  // JS Date() treats bare strings as local time, so append Z to force UTC.
+  return new Date(st.endsWith('Z') ? st : st + 'Z').getTime()
+}
+
 function calcActiveSeconds(startTimes: string[]): number {
   const now = Date.now()
   return startTimes.reduce((sum, st) => {
-    const elapsed = Math.floor((now - new Date(st).getTime()) / 1000)
+    const elapsed = Math.floor((now - parseUTCTimestamp(st)) / 1000)
     return sum + Math.max(0, elapsed)
   }, 0)
 }
 
 export function SidebarStatsBar({ resolved, active, completedMinutes, activeSessionStartTimes }: SidebarStatsBarProps) {
-  // Debug: remove after fixing
-  if (activeSessionStartTimes.length > 0) {
-    console.log('[SidebarStats] startTimes:', activeSessionStartTimes, 'calcSeconds:', calcActiveSeconds(activeSessionStartTimes), 'now:', Date.now(), 'parsed:', activeSessionStartTimes.map(st => new Date(st).getTime()))
-  }
   const [liveSeconds, setLiveSeconds] = useState(() => calcActiveSeconds(activeSessionStartTimes))
 
   // Tick every second to keep the timer in sync with the session timer