diff --git a/power/ReadVcdActivities.cc b/power/ReadVcdActivities.cc
index fa782ad3..f44c0b3a 100644
--- a/power/ReadVcdActivities.cc
+++ b/power/ReadVcdActivities.cc
@@ -62,16 +62,16 @@ setVcdActivities(Vcd &vcd,
   for (Clock *clk : *sta->sdc()->clocks())
     clk_period = min(clk->period(), clk_period);
 
-  VarTime time_max = vcd.timeMax();
+  VcdTime time_max = vcd.timeMax();
   for (VcdVar &var : vcd.vars()) {
     const VcdValues &var_values = vcd.values(var);
     if (!var_values.empty()) {
       int transition_count = 0;
       char prev_value = var_values[0].value();
-      VarTime prev_time = var_values[0].time();
-      VarTime high_time = 0;
+      VcdTime prev_time = var_values[0].time();
+      VcdTime high_time = 0;
       for (const VcdValue &var_value : var_values) {
-        VarTime time = var_value.time();
+        VcdTime time = var_value.time();
         char value = var_value.value();
         if (prev_value == '1')
           high_time += time - prev_time;
diff --git a/power/Vcd.cc b/power/Vcd.cc
index 3723bb8c..e9990cd1 100644
--- a/power/Vcd.cc
+++ b/power/Vcd.cc
@@ -64,13 +64,13 @@ Vcd::setTimeScale(double time_scale)
 }
 
 void
-Vcd::setMinDeltaTime(VarTime min_delta_time)
+Vcd::setMinDeltaTime(VcdTime min_delta_time)
 {
   min_delta_time_ = min_delta_time;
 }
 
 void
-Vcd::setTimeMax(VarTime time_max)
+Vcd::setTimeMax(VcdTime time_max)
 {
   time_max_ = time_max;
 }
@@ -96,7 +96,7 @@ Vcd::varIdValid(string &id)
 
 void
 Vcd::varAppendValue(string &id,
-                    VarTime time,
+                    VcdTime time,
                     char value)
 {
   VcdValues &values = id_values_map_[id];
@@ -105,7 +105,7 @@ Vcd::varAppendValue(string &id,
 
 void
 Vcd::varAppendBusValue(string &id,
-                       VarTime time,
+                       VcdTime time,
                        int64_t bus_value)
 {
   VcdValues &values = id_values_map_[id];
@@ -139,7 +139,7 @@ VcdVar::VcdVar(string name,
 {
 }
 
-VcdValue::VcdValue(VarTime time,
+VcdValue::VcdValue(VcdTime time,
                    char value,
                    uint64_t bus_value) :
   time_(time),
diff --git a/power/Vcd.hh b/power/Vcd.hh
index b0475fe2..2d859c19 100644
--- a/power/Vcd.hh
+++ b/power/Vcd.hh
@@ -34,7 +34,7 @@ using std::min;
 class VcdVar;
 class VcdValue;
 typedef vector<VcdValue> VcdValues;
-typedef int64_t VarTime;
+typedef int64_t VcdTime;
 typedef vector<string> VcdScope;
 
 enum class VcdVarType { wire, reg, parameter, real };
@@ -57,10 +57,10 @@ public:
   double timeUnitScale() const { return time_unit_scale_; }
   void setTimeUnit(const string &time_unit,
                    double time_unit_scale);
-  VarTime timeMax() const { return time_max_; }
-  void setTimeMax(VarTime time_max);
-  VarTime minDeltaTime() const { return min_delta_time_; }
-  void setMinDeltaTime(VarTime min_delta_time);
+  VcdTime timeMax() const { return time_max_; }
+  void setTimeMax(VcdTime time_max);
+  VcdTime minDeltaTime() const { return min_delta_time_; }
+  void setMinDeltaTime(VcdTime min_delta_time);
   vector<VcdVar> vars() { return vars_; }
   void makeVar(string &name,
                VcdVarType type,
@@ -70,10 +70,10 @@ public:
   int maxVarNameLength() const { return max_var_name_length_; }
   bool varIdValid(string &id);
   void varAppendValue(string &id,
-                      VarTime time,
+                      VcdTime time,
                       char value);
   void varAppendBusValue(string &id,
-                         VarTime time,
+                         VcdTime time,
                          int64_t bus_value);
 
 private:
@@ -88,8 +88,8 @@ private:
   size_t max_var_name_length_;
   int max_var_width_;
   map<string, VcdValues> id_values_map_;
-  VarTime min_delta_time_;
-  VarTime time_max_;
+  VcdTime min_delta_time_;
+  VcdTime time_max_;
 };
 
 class VcdVar
@@ -114,15 +114,15 @@ private:
 class VcdValue
 {
 public:
-  VcdValue(VarTime time,
+  VcdValue(VcdTime time,
            char value,
            uint64_t bus_value);
-  VarTime time() const { return time_; }
+  VcdTime time() const { return time_; }
   char value() const { return value_; }
   uint64_t busValue() const { return bus_value_; }
 
 private:
-  VarTime time_;
+  VcdTime time_;
   // 01XUZ or '\0' when width > 1 to use bus_value_.
   char value_;
   uint64_t bus_value_;
diff --git a/power/VcdReader.cc b/power/VcdReader.cc
index ed08b63a..6a02a779 100644
--- a/power/VcdReader.cc
+++ b/power/VcdReader.cc
@@ -55,8 +55,8 @@ private:
   int stmt_line_;
 
   Vcd *vcd_;
-  VarTime time_;
-  VarTime prev_time_;
+  VcdTime time_;
+  VcdTime prev_time_;
   VcdScope scope_;
 };
 
@@ -358,7 +358,7 @@ reportWaveforms(Vcd &vcd,
       size_t value_index = 0;
       VcdValue var_value = var_values[value_index];
       VcdValue prev_var_value = var_values[value_index];
-      VarTime next_value_time = var_values[value_index + 1].time();
+      VcdTime next_value_time = var_values[value_index + 1].time();
       for (double time = 0.0; time < vcd.timeMax(); time += time_delta) {
         if (time >= next_value_time) {
           if (value_index < var_values.size() - 1)