diff --git a/services/surfaceflinger/Scheduler/TimeKeeper.h b/services/surfaceflinger/Scheduler/TimeKeeper.h
index da2195c..40dd841 100644
--- a/services/surfaceflinger/Scheduler/TimeKeeper.h
+++ b/services/surfaceflinger/Scheduler/TimeKeeper.h
@@ -43,10 +43,10 @@
     virtual ~TimeKeeper();
 
     /*
-     * Arms callback to fired in time nanoseconds.
+     * Arms callback to fired when time is current based on CLOCK_MONOTONIC
      * There is only one timer, and subsequent calls will reset the callback function and the time.
      */
-    virtual void alarmIn(std::function<void()> const& callback, nsecs_t time) = 0;
+    virtual void alarmAt(std::function<void()> const& callback, nsecs_t time) = 0;
 
     /*
      * Cancels an existing pending callback
diff --git a/services/surfaceflinger/Scheduler/Timer.cpp b/services/surfaceflinger/Scheduler/Timer.cpp
index 7c5058e..59c336a 100644
--- a/services/surfaceflinger/Scheduler/Timer.cpp
+++ b/services/surfaceflinger/Scheduler/Timer.cpp
@@ -88,7 +88,7 @@
     return systemTime(SYSTEM_TIME_MONOTONIC);
 }
 
-void Timer::alarmIn(std::function<void()> const& cb, nsecs_t fireIn) {
+void Timer::alarmAt(std::function<void()> const& cb, nsecs_t time) {
     std::lock_guard<decltype(mMutex)> lk(mMutex);
     using namespace std::literals;
     static constexpr int ns_per_s =
@@ -99,11 +99,11 @@
     struct itimerspec old_timer;
     struct itimerspec new_timer {
         .it_interval = {.tv_sec = 0, .tv_nsec = 0},
-        .it_value = {.tv_sec = static_cast<long>(fireIn / ns_per_s),
-                     .tv_nsec = static_cast<long>(fireIn % ns_per_s)},
+        .it_value = {.tv_sec = static_cast<long>(time / ns_per_s),
+                     .tv_nsec = static_cast<long>(time % ns_per_s)},
     };
 
-    if (timerfd_settime(mTimerFd, 0, &new_timer, &old_timer)) {
+    if (timerfd_settime(mTimerFd, TFD_TIMER_ABSTIME, &new_timer, &old_timer)) {
         ALOGW("Failed to set timerfd %s (%i)", strerror(errno), errno);
     }
 }
diff --git a/services/surfaceflinger/Scheduler/Timer.h b/services/surfaceflinger/Scheduler/Timer.h
index a8e2d5a..69ce079 100644
--- a/services/surfaceflinger/Scheduler/Timer.h
+++ b/services/surfaceflinger/Scheduler/Timer.h
@@ -30,9 +30,9 @@
     ~Timer();
     nsecs_t now() const final;
 
-    // NB: alarmIn and alarmCancel are threadsafe; with the last-returning function being effectual
+    // NB: alarmAt and alarmCancel are threadsafe; with the last-returning function being effectual
     //     Most users will want to serialize thes calls so as to be aware of the timer state.
-    void alarmIn(std::function<void()> const& cb, nsecs_t fireIn) final;
+    void alarmAt(std::function<void()> const& cb, nsecs_t time) final;
     void alarmCancel() final;
     void dump(std::string& result) const final;
 
diff --git a/services/surfaceflinger/Scheduler/VSyncDispatchTimerQueue.cpp b/services/surfaceflinger/Scheduler/VSyncDispatchTimerQueue.cpp
index 2a6fd05..ef92680 100644
--- a/services/surfaceflinger/Scheduler/VSyncDispatchTimerQueue.cpp
+++ b/services/surfaceflinger/Scheduler/VSyncDispatchTimerQueue.cpp
@@ -180,10 +180,10 @@
     mTimeKeeper->alarmCancel();
 }
 
-void VSyncDispatchTimerQueue::setTimer(nsecs_t targetTime, nsecs_t now) {
+void VSyncDispatchTimerQueue::setTimer(nsecs_t targetTime, nsecs_t /*now*/) {
     mIntendedWakeupTime = targetTime;
-    mTimeKeeper->alarmIn(std::bind(&VSyncDispatchTimerQueue::timerCallback, this),
-                         targetTime - now);
+    mTimeKeeper->alarmAt(std::bind(&VSyncDispatchTimerQueue::timerCallback, this),
+                         mIntendedWakeupTime);
     mLastTimerSchedule = mTimeKeeper->now();
 }