diff -r efd9c589177a -r c0b4a8b5a012 toolkit/javascript/d3/test/time/hours-test.js
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/toolkit/javascript/d3/test/time/hours-test.js	Thu Apr 10 14:20:23 2014 +0200
@@ -0,0 +1,135 @@
+require("../env");
+require("../../d3");
+require("../../d3.time");
+
+var vows = require("vows"),
+    assert = require("assert");
+
+var suite = vows.describe("d3.time.hours");
+
+suite.addBatch({
+  "hours": {
+    topic: function() {
+      return d3.time.hours;
+    },
+    "returns hours": function(range) {
+      assert.deepEqual(range(local(2010, 11, 31, 12, 30), local(2010, 11, 31, 15, 30)), [
+        local(2010, 11, 31, 13),
+        local(2010, 11, 31, 14),
+        local(2010, 11, 31, 15)
+      ]);
+    },
+    "has an inclusive lower bound": function(range) {
+      assert.deepEqual(range(local(2010, 11, 31, 23), local(2011, 0, 1, 2))[0], local(2010, 11, 31, 23));
+    },
+    "has an exclusive upper bound": function(range) {
+      assert.deepEqual(range(local(2010, 11, 31, 23), local(2011, 0, 1, 2))[2], local(2011, 0, 1, 1));
+    },
+    "can skip hours": function(range) {
+      assert.deepEqual(range(local(2011, 1, 1, 1), local(2011, 1, 1, 13), 3), [
+        local(2011, 1, 1, 3),
+        local(2011, 1, 1, 6),
+        local(2011, 1, 1, 9),
+        local(2011, 1, 1, 12)
+      ]);
+    },
+    "observes start of daylight savings time": function(range) {
+      assert.deepEqual(range(local(2011, 2, 13, 1), local(2011, 2, 13, 5)), [
+        utc(2011, 2, 13, 9),
+        utc(2011, 2, 13, 10),
+        utc(2011, 2, 13, 11)
+      ]);
+    },
+    "observes end of daylight savings time": function(range) {
+      assert.deepEqual(range(local(2011, 10, 6, 0), local(2011, 10, 6, 2)), [
+        utc(2011, 10, 6, 7),
+        utc(2011, 10, 6, 8),
+        utc(2011, 10, 6, 9)
+      ]);
+    },
+    "NPT": {
+      "observes 15-minute offset": tz("Asia/Kathmandu", function(range) {
+        assert.deepEqual(range(local(2011, 10, 7, 0), local(2011, 10, 7, 3)), [
+          utc(2011, 10, 6, 18, 15),
+          utc(2011, 10, 6, 19, 15),
+          utc(2011, 10, 6, 20, 15)
+        ]);
+      })
+    },
+    "IST": {
+      "observes 30-minute offset": tz("Asia/Calcutta", function(range) {
+        assert.deepEqual(range(local(2011, 10, 7, 0), local(2011, 10, 7, 3)), [
+          utc(2011, 10, 6, 18, 30),
+          utc(2011, 10, 6, 19, 30),
+          utc(2011, 10, 6, 20, 30)
+        ]);
+      })
+    },
+    "UTC": {
+      topic: function(range) {
+        return range.utc;
+      },
+      "returns hours": function(range) {
+        assert.deepEqual(range(utc(2010, 11, 31, 12, 30), utc(2010, 11, 31, 15, 30)), [
+          utc(2010, 11, 31, 13),
+          utc(2010, 11, 31, 14),
+          utc(2010, 11, 31, 15)
+        ]);
+      },
+      "has an inclusive lower bound": function(range) {
+        assert.deepEqual(range(utc(2010, 11, 31, 23), utc(2011, 0, 1, 2))[0], utc(2010, 11, 31, 23));
+      },
+      "has an exclusive upper bound": function(range) {
+        assert.deepEqual(range(utc(2010, 11, 31, 23), utc(2011, 0, 1, 2))[2], utc(2011, 0, 1, 1));
+      },
+      "can skip hours": function(range) {
+        assert.deepEqual(range(utc(2011, 1, 1, 1), utc(2011, 1, 1, 13), 3), [
+          utc(2011, 1, 1, 3),
+          utc(2011, 1, 1, 6),
+          utc(2011, 1, 1, 9),
+          utc(2011, 1, 1, 12)
+        ]);
+      },
+      "observes start of daylight savings time": function(range) {
+        assert.deepEqual(range(utc(2011, 2, 13, 9), utc(2011, 2, 13, 12)), [
+          utc(2011, 2, 13, 9),
+          utc(2011, 2, 13, 10),
+          utc(2011, 2, 13, 11)
+        ]);
+      },
+      "observes end of daylight savings time": function(range) {
+        assert.deepEqual(range(utc(2011, 10, 6, 7), utc(2011, 10, 6, 10)), [
+          utc(2011, 10, 6, 7),
+          utc(2011, 10, 6, 8),
+          utc(2011, 10, 6, 9)
+        ]);
+      }
+    }
+  }
+});
+
+function local(year, month, day, hours, minutes, seconds) {
+  return new Date(year, month, day, hours || 0, minutes || 0, seconds || 0);
+}
+
+function utc(year, month, day, hours, minutes, seconds) {
+  return new Date(Date.UTC(year, month, day, hours || 0, minutes || 0, seconds || 0));
+}
+
+function tz(tz, scope) {
+  return function() {
+    var o = process.env.TZ;
+    try {
+      process.env.TZ = tz;
+      new Date(0).toString(); // invalidate node's dst cache
+      new Date().toString();
+      scope.apply(this, arguments);
+    } finally {
+      process.env.TZ = o;
+      new Date(0).toString(); // invalidate node's dst cache
+      new Date().toString();
+    }
+  };
+}
+
+suite.export(module);