diff --git a/core/java/android/hardware/input/VirtualKeyEvent.java b/core/java/android/hardware/input/VirtualKeyEvent.java
index c0102bf..da959af 100644
--- a/core/java/android/hardware/input/VirtualKeyEvent.java
+++ b/core/java/android/hardware/input/VirtualKeyEvent.java
@@ -286,6 +286,10 @@
          * obtained from {@link SystemClock#uptimeMillis()} (with nanosecond precision instead of
          * millisecond), but can be different depending on the use case.
          * This field is optional and can be omitted.
+         * <p>
+         * If this field is unset, then the time at which this event is sent to the framework would
+         * be considered as the event time (even though
+         * {@link VirtualKeyEvent#getEventTimeNanos()}) would return {@code 0L}).
          *
          * @return this builder, to allow for chaining of calls
          * @see InputEvent#getEventTime()
diff --git a/core/java/android/hardware/input/VirtualMouseButtonEvent.java b/core/java/android/hardware/input/VirtualMouseButtonEvent.java
index fc42b15..333c3c7 100644
--- a/core/java/android/hardware/input/VirtualMouseButtonEvent.java
+++ b/core/java/android/hardware/input/VirtualMouseButtonEvent.java
@@ -197,6 +197,10 @@
          * obtained from {@link SystemClock#uptimeMillis()} (with nanosecond precision instead of
          * millisecond), but can be different depending on the use case.
          * This field is optional and can be omitted.
+         * <p>
+         * If this field is unset, then the time at which this event is sent to the framework would
+         * be considered as the event time (even though
+         * {@link VirtualMouseButtonEvent#getEventTimeNanos()}) would return {@code 0L}).
          *
          * @return this builder, to allow for chaining of calls
          * @see InputEvent#getEventTime()
diff --git a/core/java/android/hardware/input/VirtualMouseRelativeEvent.java b/core/java/android/hardware/input/VirtualMouseRelativeEvent.java
index 2a42cfc..86d759d 100644
--- a/core/java/android/hardware/input/VirtualMouseRelativeEvent.java
+++ b/core/java/android/hardware/input/VirtualMouseRelativeEvent.java
@@ -135,6 +135,10 @@
          * obtained from {@link SystemClock#uptimeMillis()} (with nanosecond precision instead of
          * millisecond), but can be different depending on the use case.
          * This field is optional and can be omitted.
+         * <p>
+         * If this field is unset, then the time at which this event is sent to the framework would
+         * be considered as the event time (even though
+         * {@link VirtualMouseRelativeEvent#getEventTimeNanos()}) would return {@code 0L}).
          *
          * @return this builder, to allow for chaining of calls
          * @see InputEvent#getEventTime()
diff --git a/core/java/android/hardware/input/VirtualMouseScrollEvent.java b/core/java/android/hardware/input/VirtualMouseScrollEvent.java
index c89c188..a4958c7 100644
--- a/core/java/android/hardware/input/VirtualMouseScrollEvent.java
+++ b/core/java/android/hardware/input/VirtualMouseScrollEvent.java
@@ -146,6 +146,10 @@
          * obtained from {@link SystemClock#uptimeMillis()} (with nanosecond precision instead of
          * millisecond), but can be different depending on the use case.
          * This field is optional and can be omitted.
+         * <p>
+         * If this field is unset, then the time at which this event is sent to the framework would
+         * be considered as the event time (even though
+         * {@link VirtualMouseScrollEvent#getEventTimeNanos()}) would return {@code 0L}).
          *
          * @return this builder, to allow for chaining of calls
          * @see InputEvent#getEventTime()
diff --git a/core/java/android/hardware/input/VirtualRotaryEncoderScrollEvent.java b/core/java/android/hardware/input/VirtualRotaryEncoderScrollEvent.java
index 8c98abd..033b1c1 100644
--- a/core/java/android/hardware/input/VirtualRotaryEncoderScrollEvent.java
+++ b/core/java/android/hardware/input/VirtualRotaryEncoderScrollEvent.java
@@ -129,6 +129,10 @@
          * obtained from {@link SystemClock#uptimeMillis()} (with nanosecond precision instead of
          * millisecond), but can be different depending on the use case.
          * This field is optional and can be omitted.
+         * <p>
+         * If this field is unset, then the time at which this event is sent to the framework would
+         * be considered as the event time (even though
+         * {@link VirtualRotaryEncoderScrollEvent#getEventTimeNanos()}) would return {@code 0L}).
          *
          * @return this builder, to allow for chaining of calls
          * @see InputEvent#getEventTime()
diff --git a/core/java/android/hardware/input/VirtualStylusButtonEvent.java b/core/java/android/hardware/input/VirtualStylusButtonEvent.java
index 97a4cd0..8fcf561b 100644
--- a/core/java/android/hardware/input/VirtualStylusButtonEvent.java
+++ b/core/java/android/hardware/input/VirtualStylusButtonEvent.java
@@ -187,6 +187,10 @@
          * obtained from {@link SystemClock#uptimeMillis()} (with nanosecond precision instead of
          * millisecond), but can be different depending on the use case.
          * This field is optional and can be omitted.
+         * <p>
+         * If this field is unset, then the time at which this event is sent to the framework would
+         * be considered as the event time (even though
+         * {@link VirtualStylusButtonEvent#getEventTimeNanos()}) would return {@code 0L}).
          *
          * @return this builder, to allow for chaining of calls
          * @see InputEvent#getEventTime()
diff --git a/core/java/android/hardware/input/VirtualStylusMotionEvent.java b/core/java/android/hardware/input/VirtualStylusMotionEvent.java
index 2ab76ae..0ac6f3a 100644
--- a/core/java/android/hardware/input/VirtualStylusMotionEvent.java
+++ b/core/java/android/hardware/input/VirtualStylusMotionEvent.java
@@ -377,6 +377,10 @@
          * obtained from {@link SystemClock#uptimeMillis()} (with nanosecond precision instead of
          * millisecond), but can be different depending on the use case.
          * This field is optional and can be omitted.
+         * <p>
+         * If this field is unset, then the time at which this event is sent to the framework would
+         * be considered as the event time (even though
+         * {@link VirtualStylusMotionEvent#getEventTimeNanos()}) would return {@code 0L}).
          *
          * @return this builder, to allow for chaining of calls
          * @see InputEvent#getEventTime()
diff --git a/core/java/android/hardware/input/VirtualTouchEvent.java b/core/java/android/hardware/input/VirtualTouchEvent.java
index 7936dfe..0cccd25 100644
--- a/core/java/android/hardware/input/VirtualTouchEvent.java
+++ b/core/java/android/hardware/input/VirtualTouchEvent.java
@@ -354,6 +354,10 @@
          * obtained from {@link SystemClock#uptimeMillis()} (with nanosecond precision instead of
          * millisecond), but can be different depending on the use case.
          * This field is optional and can be omitted.
+         * <p>
+         * If this field is unset, then the time at which this event is sent to the framework would
+         * be considered as the event time (even though
+         * {@link VirtualTouchEvent#getEventTimeNanos()}) would return {@code 0L}).
          *
          * @return this builder, to allow for chaining of calls
          * @see InputEvent#getEventTime()