diff --git a/web/src/hooks/useTimeTracking.ts b/web/src/hooks/useTimeTracking.ts
index 81ac61b3..5d53be71 100644
--- a/web/src/hooks/useTimeTracking.ts
+++ b/web/src/hooks/useTimeTracking.ts
@@ -14,6 +14,17 @@ export function useTimeSummary() {
   });
 }
 
+/**
+ * Optimistically replace a task in the tasks list cache so the UI
+ * updates immediately without waiting for a background refetch.
+ */
+function patchTaskInList(queryClient: ReturnType<typeof useQueryClient>, updated: Task) {
+  queryClient.setQueryData<Task[]>(['tasks'], (old) =>
+    old ? old.map((t) => (t.id === updated.id ? updated : t)) : old
+  );
+  queryClient.setQueryData(['tasks', updated.id], updated);
+}
+
 /**
  * Start timer for a task
  */
@@ -23,8 +34,8 @@ export function useStartTimer() {
   return useMutation<Task, Error, string>({
     mutationFn: (taskId) => api.time.start(taskId),
     onSuccess: (task) => {
+      patchTaskInList(queryClient, task);
       queryClient.invalidateQueries({ queryKey: ['tasks'] });
-      queryClient.setQueryData(['tasks', task.id], task);
       queryClient.invalidateQueries({ queryKey: ['time', 'summary'] });
     },
   });
@@ -39,8 +50,8 @@ export function useStopTimer() {
   return useMutation<Task, Error, string>({
     mutationFn: (taskId) => api.time.stop(taskId),
     onSuccess: (task) => {
+      patchTaskInList(queryClient, task);
       queryClient.invalidateQueries({ queryKey: ['tasks'] });
-      queryClient.setQueryData(['tasks', task.id], task);
       queryClient.invalidateQueries({ queryKey: ['time', 'summary'] });
     },
   });
@@ -53,10 +64,11 @@ export function useAddTimeEntry() {
   const queryClient = useQueryClient();
 
   return useMutation<Task, Error, { taskId: string; duration: number; description?: string }>({
-    mutationFn: ({ taskId, duration, description }) => api.time.addEntry(taskId, duration, description),
+    mutationFn: ({ taskId, duration, description }) =>
+      api.time.addEntry(taskId, duration, description),
     onSuccess: (task) => {
+      patchTaskInList(queryClient, task);
       queryClient.invalidateQueries({ queryKey: ['tasks'] });
-      queryClient.setQueryData(['tasks', task.id], task);
       queryClient.invalidateQueries({ queryKey: ['time', 'summary'] });
     },
   });
@@ -71,8 +83,8 @@ export function useDeleteTimeEntry() {
   return useMutation<Task, Error, { taskId: string; entryId: string }>({
     mutationFn: ({ taskId, entryId }) => api.time.deleteEntry(taskId, entryId),
     onSuccess: (task) => {
+      patchTaskInList(queryClient, task);
       queryClient.invalidateQueries({ queryKey: ['tasks'] });
-      queryClient.setQueryData(['tasks', task.id], task);
       queryClient.invalidateQueries({ queryKey: ['time', 'summary'] });
     },
   });
@@ -85,19 +97,19 @@ export function formatDuration(seconds: number): string {
   if (seconds < 60) {
     return `${seconds}s`;
   }
-  
+
   const hours = Math.floor(seconds / 3600);
   const minutes = Math.floor((seconds % 3600) / 60);
   const secs = seconds % 60;
-  
+
   if (hours > 0) {
     return `${hours}h ${minutes}m`;
   }
-  
+
   if (minutes > 0 && secs > 0) {
     return `${minutes}m ${secs}s`;
   }
-  
+
   return `${minutes}m`;
 }
 
@@ -106,29 +118,29 @@ export function formatDuration(seconds: number): string {
  */
 export function parseDuration(input: string): number | null {
   const trimmed = input.trim().toLowerCase();
-  
+
   // Try parsing as plain number (minutes)
   if (/^\d+$/.test(trimmed)) {
     return parseInt(trimmed, 10) * 60;
   }
-  
+
   // Try parsing with units
   let totalSeconds = 0;
-  
+
   const hourMatch = trimmed.match(/(\d+)\s*h/);
   if (hourMatch) {
     totalSeconds += parseInt(hourMatch[1], 10) * 3600;
   }
-  
+
   const minMatch = trimmed.match(/(\d+)\s*m/);
   if (minMatch) {
     totalSeconds += parseInt(minMatch[1], 10) * 60;
   }
-  
+
   const secMatch = trimmed.match(/(\d+)\s*s/);
   if (secMatch) {
     totalSeconds += parseInt(secMatch[1], 10);
   }
-  
+
   return totalSeconds > 0 ? totalSeconds : null;
 }