diff --git a/src/gui/MainWindow.cpp b/src/gui/MainWindow.cpp
index 08cc757..2f2f0e0 100644
--- a/src/gui/MainWindow.cpp
+++ b/src/gui/MainWindow.cpp
@@ -34,7 +34,7 @@ void loadData(float* d_data, const int idx, const int timestep) {
   for (int i = 0; i < VOLUME_WIDTH * VOLUME_HEIGHT * VOLUME_DEPTH; i++) {
     hostVolume[i] = h_data[i + timestep*VOLUME_DEPTH*VOLUME_HEIGHT*VOLUME_WIDTH];
     // Discard missing values
-    if (h_data[i + 0*VOLUME_DEPTH*VOLUME_HEIGHT*VOLUME_WIDTH] + epsilon >= infty) hostVolume[i] = -infty;
+    if (h_data[i + timestep*VOLUME_DEPTH*VOLUME_HEIGHT*VOLUME_WIDTH] + epsilon >= infty) hostVolume[i] = -infty;
   }
   std::cout << "hi\n";
 
diff --git a/src/gui/input/Widget.cpp b/src/gui/input/Widget.cpp
index c1fb603..a415b7b 100644
--- a/src/gui/input/Widget.cpp
+++ b/src/gui/input/Widget.cpp
@@ -169,7 +169,9 @@ void Widget::tick(double fps) {
   }
   ImGui::SameLine();
   ImGui::Text(this->dateString);
-  ImGui::DragInt("time step to load", &this->timestep, 1, 0, 3, "%d", ImGuiSliderFlags_AlwaysClamp);
+  if (ImGui::DragInt("time step to load", &this->timestep, 1, 0, 3, "%d", ImGuiSliderFlags_AlwaysClamp)) {
+    this->dateChanged = true;
+  }
   ImGui::DragInt("Samples per pixel", &this->samplesPerPixel, 1, 1, 16, "%d", ImGuiSliderFlags_AlwaysClamp);
   if (ImGui::Button("Save render")) this->saveImage = true;
   ImGui::End();
diff --git a/src/gui/input/Widget.h b/src/gui/input/Widget.h
index 546caa7..45ad51d 100644
--- a/src/gui/input/Widget.h
+++ b/src/gui/input/Widget.h
@@ -14,6 +14,7 @@ public:
   bool dateChanged;
   bool saveImage;
   int date;
+  int timestep;
 
   void tick(double fps);
   void render();
@@ -34,7 +35,6 @@ private:
   ImGuiIO io;
   char *dateString;
   int samplesPerPixel;
-  int timestep;
 
   // transfer function controls
   int tfComboSelected;