diff --git a/javascript/JZZ.js b/javascript/JZZ.js
index 11146c7..99e5130 100644
--- a/javascript/JZZ.js
+++ b/javascript/JZZ.js
@@ -2916,10 +2916,12 @@
 
   var _helperNN = {
     noop: function() { return [0, 0, 0, 0]; },
-    ticksPQN: function(n) { n = _16b(n); return [0, 0x30, n >> 8, n & 0xff]; },
-    delta: function(n) { n = _20b(n); return [0, 0x40 + (n >> 16), (n >> 8) & 0xff, n & 0xff]; },
-    clipStart: function() { return [0xf0, 0x20, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0]; },
-    clipEnd: function() { return [0xf0, 0x21, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0]; },
+    umpClock: function(n) { n = _16b(n); return [0, 0x10, n >> 8, n & 0xff]; },
+    umpTimestamp: function(n) { n = _16b(n); return [0, 0x20, n >> 8, n & 0xff]; },
+    umpTicksPQN: function(n) { n = _16b(n); return [0, 0x30, n >> 8, n & 0xff]; },
+    umpDelta: function(n) { n = n || 0; n = _20b(n); return [0, 0x40 + (n >> 16), (n >> 8) & 0xff, n & 0xff]; },
+    umpStartClip: function() { return [0xf0, 0x20, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0]; },
+    umpEndClip: function() { return [0xf0, 0x21, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0]; },
   };
   var _helperGC = {
   };
diff --git a/test/common.js b/test/common.js
index 05319aa..29207c9 100644
--- a/test/common.js
+++ b/test/common.js
@@ -846,21 +846,28 @@ describe('UMP messages', function() {
   it('sxMidiSoft', function() {
     assert.equal(JZZ.UMP.sxMidiSoft(5, 4, 'karaoke...').toString(), '35160020 2400046b,35266172 616f6b65,35332e2e 2e000000');
   });
-  it('ticksPQN', function() {
-    assert.equal(JZZ.UMP.ticksPQN(96).toString(), '00300060');
-    assert.throws(function() { JZZ.UMP.ticksPQN(0x10000); });
+  it('umpClock', function() {
+    assert.equal(JZZ.UMP.umpClock(96).toString(), '00100060');
   });
-  it('delta', function() {
-    assert.equal(JZZ.UMP.delta(96).toString(), '00400060');
-    assert.throws(function() { JZZ.UMP.delta(0x100000); });
+  it('umpTimestamp', function() {
+    assert.equal(JZZ.UMP.umpTimestamp(96).toString(), '00200060');
   });
-  it('clipStart', function() {
-    var msg = JZZ.UMP.clipStart();
+  it('umpTicksPQN', function() {
+    assert.equal(JZZ.UMP.umpTicksPQN(96).toString(), '00300060');
+    assert.throws(function() { JZZ.UMP.umpTicksPQN(0x10000); });
+  });
+  it('umpDelta', function() {
+    assert.equal(JZZ.UMP.umpDelta().toString(), '00400000');
+    assert.equal(JZZ.UMP.umpDelta(96).toString(), '00400060');
+    assert.throws(function() { JZZ.UMP.umpDelta(0x100000); });
+  });
+  it('umpStartClip', function() {
+    var msg = JZZ.UMP.umpStartClip();
     assert.equal(typeof msg.getGroup(), 'undefined');
     assert.equal(msg.toString(), 'f0200000 00000000 00000000 00000000');
   });
-  it('clipEnd', function() {
-    assert.equal(JZZ.UMP.clipEnd().toString(), 'f0210000 00000000 00000000 00000000');
+  it('umpEndClip', function() {
+    assert.equal(JZZ.UMP.umpEndClip().toString(), 'f0210000 00000000 00000000 00000000');
   });
 });