diff --git a/src/renderview.js b/src/renderview.js
index 69075a2..61b2808 100644
--- a/src/renderview.js
+++ b/src/renderview.js
@@ -69,7 +69,7 @@ function getModifiers (ev) {
 }
 
 function getTimestamp () {
-  return Date.now() / 1000
+  return performance.now() / 1000
 }
 
 function arraysEqual (a, b) {
@@ -395,7 +395,7 @@ class BaseRenderView {
         this._isVisible = isVisible
         const event = {
           event_type: isVisible ? 'show' : 'hide',
-          time_stamp: getTimestamp()
+          t: getTimestamp()
         }
         this.onEvent(event)
       }
@@ -462,7 +462,7 @@ class BaseRenderView {
         pwidth: physicalWidth,
         pheight: physicalHeight,
         pixel_ratio: ratio,
-        time_stamp: getTimestamp()
+        timestamp: getTimestamp()
       }
       this.onEvent(event)
     })
@@ -509,7 +509,7 @@ class BaseRenderView {
         modifiers,
         ntouches: 0, // TODO later: maybe via https://developer.mozilla.org/en-US/docs/Web/API/TouchEvent
         touches: {},
-        time_stamp: getTimestamp()
+        timestamp: getTimestamp()
       }
       this.onEvent(event)
     },
@@ -560,7 +560,7 @@ class BaseRenderView {
           modifiers,
           ntouches: 0,
           touches: {},
-          time_stamp: getTimestamp()
+          timestamp: getTimestamp()
         }
         if (this._moveThrottle > 0) {
           sendMoveEvent() // Send previous (if any)
@@ -595,7 +595,7 @@ class BaseRenderView {
         modifiers,
         ntouches: 0,
         touches: {},
-        time_stamp: getTimestamp()
+        timestamp: getTimestamp()
       }
       this.onEvent(event)
     },
@@ -624,7 +624,7 @@ class BaseRenderView {
         modifiers,
         ntouches: 0,
         touches: {},
-        time_stamp: getTimestamp()
+        timestamp: getTimestamp()
       }
       this.onEvent(event)
     },
@@ -653,7 +653,7 @@ class BaseRenderView {
         modifiers,
         ntouches: 0,
         touches: {},
-        time_stamp: getTimestamp()
+        timestamp: getTimestamp()
       }
       this.onEvent(event)
     },
@@ -682,7 +682,7 @@ class BaseRenderView {
         buttons,
         modifiers,
         // no touches here
-        time_stamp: getTimestamp()
+        timestamp: getTimestamp()
       }
       this.onEvent(event)
     },
@@ -736,7 +736,7 @@ class BaseRenderView {
           dy: ev.deltaY * scale,
           buttons,
           modifiers,
-          time_stamp: getTimestamp()
+          timestamp: getTimestamp()
         }
         if (this._wheelThrottle > 0) {
           sendWheelEvent() // Send previous (if any)
@@ -769,7 +769,7 @@ class BaseRenderView {
         event_type: 'key_down',
         key: KEY_MAP[ev.key] || ev.key,
         modifiers,
-        time_stamp: getTimestamp()
+        timestamp: getTimestamp()
       }
       this.onEvent(event)
     },
@@ -787,7 +787,7 @@ class BaseRenderView {
         event_type: 'key_up',
         key: KEY_MAP[ev.key] || ev.key,
         modifiers,
-        time_stamp: getTimestamp()
+        timestamp: getTimestamp()
       }
       this.onEvent(event)
     },
@@ -810,7 +810,7 @@ class BaseRenderView {
         is_composing: ev.isComposing,
         input_type: ev.inputType,
         // repeat: ev.repeat,  // n.a.
-        time_stamp: getTimestamp()
+        timestamp: getTimestamp()
       }
       this.onEvent(event)
     },
diff --git a/src/spec.md b/src/spec.md
index 94f8426..e014db7 100644
--- a/src/spec.md
+++ b/src/spec.md
@@ -71,7 +71,7 @@ Fields:
 * `pwidth`: The width in physical pixels.
 * `pheight`: The height in physical pixels.
 * `pixel_ratio`: The pixel ratio between logical and physical pixels.
-* `time_stamp`: A timestamp in seconds.
+* `timestamp`: A timestamp in seconds.
 
 
 ### close
@@ -81,7 +81,7 @@ This event is emitted when the canvas is closed (i.e. destroyed).
 Fields:
 
 * `event_type`: 'close'
-* `time_stamp`: A timestamp in seconds.
+* `timestamp`: A timestamp in seconds.
 
 
 ### show
@@ -93,7 +93,7 @@ shown. If this is not the case, the implementation should emit a 'hide' event.
 Fields:
 
 * `event_type`: 'show'
-* `time_stamp`: A timestamp in seconds.
+* `timestamp`: A timestamp in seconds.
 
 
 ### hide
@@ -103,7 +103,7 @@ This event is emitted when the canvas is hidden. It can e.g. be minimized or scr
 Fields:
 
 * `event_type`: 'hide'
-* `time_stamp`: A timestamp in seconds.
+* `timestamp`: A timestamp in seconds.
 
 
 ### pointer_down
@@ -120,7 +120,7 @@ Fields:
 * `modifiers`: A tuple of modifier keys being pressed down.
 * `ntouches`: Experimental.
 * `touches`: Experimental.
-* `time_stamp`: A timestamp in seconds.
+* `timestamp`: A timestamp in seconds.
 
 The mouse buttons are defined as follows, which is different from JavaScript (although close to the JS `buttons` bitmask):
 
@@ -162,7 +162,7 @@ This event is emitted when the user moves a pointer into the boundary of the can
 Fields:
 
 * `event_type`: 'pointer_enter'
-* `time_stamp`: A timestamp in seconds.
+* `timestamp`: A timestamp in seconds.
 
 
 ### pointer_leave
@@ -172,7 +172,7 @@ This event is emitted when the user moves a pointer out of the boundary of the c
 Fields:
 
 * `event_type`: 'pointer_enter'
-* `time_stamp`: A timestamp in seconds.
+* `timestamp`: A timestamp in seconds.
 
 
 ### double_click
@@ -187,7 +187,7 @@ Fields:
 * `button`: The button to which this event applies.
 * `buttons`: A tuple of buttons being pressed down.
 * `modifiers`: A tuple of modifier keys being pressed down. See section below for details.
-* `time_stamp`: A timestamp in seconds.
+* `timestamp`: A timestamp in seconds.
 
 
 ### wheel
@@ -205,7 +205,7 @@ Fields:
 * `y`: The mouse vertical position during the scroll.
 * `buttons`: aA tuple of buttons being pressed down.
 * `modifiers` *: A tuple of modifier keys being pressed down.
-* `time_stamp`: A timestamp in seconds.
+* `timestamp`: A timestamp in seconds.
 
 Similar to the JS wheel event, the values of the deltas depend on the
 platform and whether the mouse-wheel, trackpad or a touch-gesture is
@@ -230,7 +230,7 @@ Fields:
 * `event_type`: 'key_down'
 * `key`: The key being pressed as a string.
 * `modifiers`: A tuple of modifier keys being pressed down.
-* `time_stamp`: A timestamp in seconds.
+* `timestamp`: A timestamp in seconds.
 
 The key names follow the [browser spec](https://developer.mozilla.org/en-US/docs/Web/API/KeyboardEvent).
 
@@ -247,7 +247,7 @@ This event is emitted when a key is released.
 * `event_type`: 'key_up'
 * `key`: The key being released as a string.
 * `modifiers`: A tuple of modifier keys being pressed down.
-* `time_stamp`: A timestamp in seconds.
+* `timestamp`: A timestamp in seconds.
 
 
 ### char
@@ -267,10 +267,11 @@ Fields:
 ## Details
 
 
-### Time stamps
+### Timestamps
 
-The reference for the used time stamps is not defined by this spec. They could be Unix timestamps or something that starts at application start.
-In multi-process environments you can therefore not compare the timestamps to e.g. `time.time()`.
+The timestamps are intended to compare the time *between* events. The reference
+for the used time stamps is not defined by this spec. They could be Unix
+timestamps or something like `time.perf_counter()`.
 
 
 ### Coordinate frame
diff --git a/src/tester.html b/src/tester.html
index 4d6f8f4..7e940ad 100644
--- a/src/tester.html
+++ b/src/tester.html
@@ -76,7 +76,7 @@
             }
         }
 
-        const floatKeys = ['x', 'y', 'dx', 'dy', 'time_stamp']
+        const floatKeys = ['x', 'y', 'dx', 'dy', 'timestamp']
         function eventToString(event) {
             let s = '{ '
             for (let [key, value] of Object.entries(event)) {