diff --git a/package.json b/package.json
index f3bc3c115a..ec849e9def 100644
--- a/package.json
+++ b/package.json
@@ -24,9 +24,10 @@
     "snyk-protect": "snyk protect",
     "prepublish": "npm run snyk-protect",
     "test-challenges": "babel-node seed/test-challenges.js | tap-spec",
-    "test-js": "npm run test-js-client && npm run test-js-common",
+    "test-js": "npm run test-js-client && npm run test-js-common && npm run test-js-server",
     "test-js-client": "tape -r babel-register 'client/**/*.test.js' | tap-spec",
     "test-js-common": "tape -r babel-register 'common/**/*.test.js' | tap-spec",
+    "test-js-server": "tape -r babel-register 'server/**/*.test.js' | tap-spec",
     "test": "npm run test-js && npm run test-challenges",
     "cover": "babel-node ./node_modules/.bin/babel-istanbul cover tape common/**/*.test.js",
     "coveralls": "npm run cover && istanbul-coveralls"
@@ -167,4 +168,4 @@
     "yargs": "^5.0.0"
   },
   "snyk": true
-}
\ No newline at end of file
+}
diff --git a/server/utils/date-utils.test.js b/server/utils/date-utils.test.js
new file mode 100644
index 0000000000..18ebc792f1
--- /dev/null
+++ b/server/utils/date-utils.test.js
@@ -0,0 +1,75 @@
+import moment from 'moment-timezone';
+
+import { dayCount } from './date-utils';
+import test from 'tape';
+
+const PST = 'America/Los_Angeles';
+
+test('Day count between two epochs (inclusive) calculation', function(t) {
+  t.plan(7);
+
+  t.equal(
+    dayCount([
+      moment.utc('8/3/2015 3:00', 'M/D/YYYY H:mm').valueOf(),
+      moment.utc('8/3/2015 2:00', 'M/D/YYYY H:mm').valueOf()
+    ]),
+    1,
+    'should return 1 day given epochs of the same day'
+  );
+
+  t.equal(
+    dayCount([
+      moment.utc('8/3/2015 2:00', 'M/D/YYYY H:mm').valueOf(),
+      moment.utc('8/3/2015 2:00', 'M/D/YYYY H:mm').valueOf()
+    ]),
+    1,
+    'should return 1 day given same epochs'
+  );
+
+  t.equal(
+    dayCount([
+      moment.utc('8/4/2015 2:00', 'M/D/YYYY H:mm').valueOf(),
+      moment.utc('8/3/2015 2:00', 'M/D/YYYY H:mm').valueOf()
+    ]),
+    2,
+    'should return 2 days when there is a 24 hours difference'
+  );
+
+  t.equal(
+    dayCount([
+      moment.utc('8/4/2015 1:00', 'M/D/YYYY H:mm').valueOf(),
+      moment.utc('8/3/2015 23:00', 'M/D/YYYY H:mm').valueOf()
+    ]),
+    2,
+    'should return 2 days when the diff is less than 24h but different in UTC'
+  );
+
+  t.equal(
+    dayCount([
+      moment.utc('8/4/2015 1:00', 'M/D/YYYY H:mm').valueOf(),
+      moment.utc('8/3/2015 23:00', 'M/D/YYYY H:mm').valueOf()
+    ], PST),
+    1,
+    'should return 1 day when the diff is less than 24h ' +
+      'and days are different in UTC, but given PST'
+  );
+
+  t.equal(
+    dayCount([
+      moment.utc('10/27/2015 1:00', 'M/D/YYYY H:mm').valueOf(),
+      moment.utc('5/12/1982 1:00', 'M/D/YYYY H:mm').valueOf()
+    ]),
+    12222,
+    'should return correct count when there is very big period'
+  );
+
+  t.equal(
+    dayCount([
+      moment.utc('8/4/2015 2:00', 'M/D/YYYY H:mm').valueOf(),
+      moment.utc('8/3/2015 2:00', 'M/D/YYYY H:mm').valueOf()
+    ]),
+    2,
+    'should return 2 days when there is a 24 hours difference ' +
+      'between dates given `undefined` timezone'
+  );
+});
diff --git a/server/utils/user-stats.test.js b/server/utils/user-stats.test.js
new file mode 100644
index 0000000000..ff9b29f60f
--- /dev/null
+++ b/server/utils/user-stats.test.js
@@ -0,0 +1,429 @@
+import test from 'tape';
+import moment from 'moment-timezone';
+import sinon from 'sinon';
+
+import {
+  prepUniqueDays,
+  calcCurrentStreak,
+  calcLongestStreak
+} from './user-stats';
+
+// setting now to 2016-02-03T11:00:00 (PST)
+const clock = sinon.useFakeTimers(1454526000000);
+const PST = 'America/Los_Angeles';
+
+test('Prepare calendar items', function(t) {
+
+  t.plan(5);
+
+  t.deepEqual(
+    prepUniqueDays([
+      moment.utc('8/3/2015 2:00', 'M/D/YYYY H:mm').valueOf(),
+      moment.utc('8/3/2015 14:00', 'M/D/YYYY H:mm').valueOf(),
+      moment.utc('8/3/2015 20:00', 'M/D/YYYY H:mm').valueOf()
+    ]),
+    [1438560000000],
+    'should return correct epoch when all entries fall into one day in UTC'
+  );
+
+  t.deepEqual(
+    prepUniqueDays([
+      moment.utc('8/3/2015 2:00', 'M/D/YYYY H:mm').valueOf(),
+      moment.utc('8/3/2015 2:00', 'M/D/YYYY H:mm').valueOf()
+    ]),
+    [1438560000000],
+    'should return correct epoch when given two identical dates'
+  );
+
+
+  t.deepEqual(
+    prepUniqueDays([
+      // 8/2/2015 in America/Los_Angeles
+      moment.utc('8/3/2015 2:00', 'M/D/YYYY H:mm').valueOf(),
+      moment.utc('8/3/2015 14:00', 'M/D/YYYY H:mm').valueOf(),
+      moment.utc('8/3/2015 20:00', 'M/D/YYYY H:mm').valueOf()
+    ], PST),
+    [1438498800000, 1438585200000],
+    'should return 2 epochs when dates fall into two days in PST'
+  );
+
+  t.deepEqual(
+    prepUniqueDays([
+      moment.utc('8/1/2015 2:00', 'M/D/YYYY H:mm').valueOf(),
+      moment.utc('3/3/2015 14:00', 'M/D/YYYY H:mm').valueOf(),
+      moment.utc('9/30/2014 20:00', 'M/D/YYYY H:mm').valueOf()
+    ]),
+    [1412035200000, 1425340800000, 1438387200000],
+    'should return 3 epochs when dates fall into three days'
+  );
+
+  t.deepEqual(
+    prepUniqueDays([
+      1438387200000, 1425340800000, 1412035200000
+    ]),
+    [1412035200000, 1425340800000, 1438387200000],
+    'should return same but sorted array if all input dates are start of day'
+  );
+
+});
+
+test('Current streak calculation', function(t) {
+
+  t.plan(11);
+
+  t.equal(
+    calcCurrentStreak(
+      prepUniqueDays([
+        moment.utc(moment.utc().subtract(1, 'hours')).valueOf()
+      ])
+    ),
+    1,
+    'should return 1 day when today one challenge was completed'
+  );
+
+  t.equal(
+    calcCurrentStreak(
+      prepUniqueDays([
+        moment.utc(moment.utc().subtract(1, 'hours')).valueOf(),
+        moment.utc(moment.utc().subtract(1, 'hours')).valueOf()
+      ])
+    ),
+    1,
+    'should return 1 day when today more than one challenge was completed'
+  );
+
+  t.equal(
+    calcCurrentStreak(
+      prepUniqueDays([
+        moment.utc('9/11/2015 4:00', 'M/D/YYYY H:mm').valueOf()
+      ])
+    ),
+    0,
+    'should return 0 day when today 0 challenges were completed'
+  );
+
+  t.equal(
+    calcCurrentStreak(
+      prepUniqueDays([
+        moment.utc(moment.utc().subtract(1, 'days')).valueOf(),
+        moment.utc(moment.utc().subtract(1, 'hours')).valueOf()
+      ])
+    ),
+    2,
+    'should return 2 days when today and yesterday challenges were completed'
+  );
+
+  t.equal(
+    calcCurrentStreak(
+      prepUniqueDays([
+        moment.utc('8/3/2015 2:00', 'M/D/YYYY H:mm').valueOf(),
+        moment.utc('9/11/2015 4:00', 'M/D/YYYY H:mm').valueOf(),
+        moment.utc('9/12/2015 1:00', 'M/D/YYYY H:mm').valueOf(),
+        moment.utc('9/12/2015 1:00', 'M/D/YYYY H:mm').valueOf(),
+        moment.utc('9/12/2015 2:00', 'M/D/YYYY H:mm').valueOf(),
+        moment.utc('9/12/2015 3:00', 'M/D/YYYY H:mm').valueOf(),
+        moment.utc('9/13/2015 4:00', 'M/D/YYYY H:mm').valueOf(),
+        moment.utc('9/14/2015 5:00', 'M/D/YYYY H:mm').valueOf(),
+        moment.utc(moment.utc().subtract(2, 'days')).valueOf(),
+        moment.utc(moment.utc().subtract(1, 'days')).valueOf(),
+        moment.utc(moment.utc().subtract(1, 'hours')).valueOf()
+      ])
+    ),
+    3,
+    'should return 3 when today and for two days before user was activity'
+  );
+
+  t.equal(
+    calcCurrentStreak(
+      prepUniqueDays([
+        moment.utc(moment.utc().subtract(47, 'hours')).valueOf(),
+        moment.utc(moment.utc().subtract(11, 'hours')).valueOf()
+      ])
+    ),
+    1,
+    'should return 1 when there is 1.5 days long break and ' +
+      'dates fall into two days separated by third'
+  );
+
+  t.equal(
+    calcCurrentStreak(
+      prepUniqueDays([
+        moment.utc(moment.utc().subtract(40, 'hours')).valueOf(),
+        moment.utc(moment.utc().subtract(1, 'hours')).valueOf()
+      ])
+    ),
+    2,
+    'should return 2 when the break is more than 1.5 days ' +
+      'but dates fall into two consecutive days'
+  );
+
+  t.equal(
+    calcCurrentStreak(
+      prepUniqueDays([
+        moment.utc(moment.utc().subtract(1, 'hours')).valueOf(),
+        moment.utc(moment.utc().subtract(1, 'hours')).valueOf()
+      ])
+    ),
+    1,
+    'should return correct count in default timezone UTC ' +
+      'given `undefined` timezone'
+  );
+
+  t.equal(
+    calcCurrentStreak(
+      prepUniqueDays([
+        moment.utc(moment.utc().subtract(1, 'days')).valueOf(),
+        moment.utc(moment.utc().subtract(1, 'hours')).valueOf()
+      ], PST),
+      PST
+    ),
+    2,
+    'should return 2 days when today and yesterday ' +
+      'challenges were completed given PST'
+  );
+
+  t.equal(
+    calcCurrentStreak(
+      prepUniqueDays([
+        1453174506164, 1453175436725, 1453252466853, 1453294968225,
+        1453383782844, 1453431903117, 1453471373080, 1453594733026,
+        1453645014058, 1453746762747, 1453747659197, 1453748029416,
+        1453818029213, 1453951796007, 1453988570615, 1454069704441,
+        1454203673979, 1454294055498, 1454333545125, 1454415163903,
+        1454519128123, moment.tz(PST).valueOf()
+      ], PST),
+      PST
+    ),
+    17,
+    'should return 17 when there is no break in given timezone ' +
+      '(but would be the break if in UTC)'
+  );
+
+  t.equal(
+    calcCurrentStreak(
+      prepUniqueDays([
+        1453174506164, 1453175436725, 1453252466853, 1453294968225,
+        1453383782844, 1453431903117, 1453471373080, 1453594733026,
+        1453645014058, 1453746762747, 1453747659197, 1453748029416,
+        1453818029213, 1453951796007, 1453988570615, 1454069704441,
+        1454203673979, 1454294055498, 1454333545125, 1454415163903,
+        1454519128123, moment.utc().valueOf()
+      ])
+    ),
+    4,
+    'should return 4 when there is a break in UTC ' +
+      '(but would be no break in PST)'
+  );
+});
+
+test('Longest streak calculation', function(t) {
+  t.plan(14);
+
+  t.equal(
+    calcLongestStreak(
+      prepUniqueDays([
+        moment.utc('9/12/2015 4:00', 'M/D/YYYY H:mm').valueOf()
+      ])
+    ),
+    1,
+    'should return 1 when there is the only one one-day-long streak available'
+  );
+
+  t.equal(
+    calcLongestStreak(
+      prepUniqueDays([
+        moment.utc('9/11/2015 4:00', 'M/D/YYYY H:mm').valueOf(),
+        moment.utc('9/12/2015 2:00', 'M/D/YYYY H:mm').valueOf(),
+        moment.utc('9/13/2015 3:00', 'M/D/YYYY H:mm').valueOf(),
+        moment.utc('9/14/2015 1:00', 'M/D/YYYY H:mm').valueOf()
+      ])
+    ),
+    4,
+    'should return 4 when there is the only one ' +
+      'more-than-one-days-long streak available'
+  );
+
+  t.equal(
+    calcLongestStreak(
+      prepUniqueDays([
+        moment.utc(moment.utc().subtract(1, 'hours')).valueOf()
+      ])
+    ),
+    1,
+    'should return 1 when there is only one one-day-long streak and it is today'
+  );
+
+  t.equal(
+    calcLongestStreak(
+      prepUniqueDays([
+        moment.utc(moment.utc().subtract(1, 'days')).valueOf(),
+        moment.utc(moment.utc().subtract(1, 'hours')).valueOf()
+      ])
+    ),
+    2,
+    'should return 2 when yesterday and today makes longest streak'
+  );
+
+  t.equal(
+    calcLongestStreak(
+      prepUniqueDays([
+        moment.utc('8/3/2015 2:00', 'M/D/YYYY H:mm').valueOf(),
+        moment.utc('9/11/2015 4:00', 'M/D/YYYY H:mm').valueOf(),
+        moment.utc('9/12/2015 2:00', 'M/D/YYYY H:mm').valueOf(),
+        moment.utc('10/4/2015 1:00', 'M/D/YYYY H:mm').valueOf(),
+        moment.utc('10/5/2015 5:00', 'M/D/YYYY H:mm').valueOf(),
+        moment.utc('10/6/2015 4:00', 'M/D/YYYY H:mm').valueOf(),
+        moment.utc('10/7/2015 5:00', 'M/D/YYYY H:mm').valueOf(),
+        moment.utc('11/3/2015 2:00', 'M/D/YYYY H:mm').valueOf()
+      ])
+    ),
+    4,
+    'should return 4 when there is a month long break'
+  );
+
+  t.equal(
+    calcLongestStreak(
+      prepUniqueDays([
+        moment.utc('8/3/2015 2:00', 'M/D/YYYY H:mm').valueOf(),
+        moment.utc('9/11/2015 4:00', 'M/D/YYYY H:mm').valueOf(),
+        moment.utc('9/12/2015 15:30', 'M/D/YYYY H:mm').valueOf(),
+        moment.utc(moment.utc('9/12/2015 15:30', 'M/D/YYYY H:mm')
+          .add(37, 'hours')).valueOf(),
+
+        moment.utc('9/14/2015 22:00', 'M/D/YYYY H:mm').valueOf(),
+        moment.utc('9/15/2015 4:00', 'M/D/YYYY H:mm').valueOf(),
+        moment.utc('10/3/2015 2:00', 'M/D/YYYY H:mm').valueOf()
+      ])
+    ),
+    2,
+    'should return 2 when there is a more than 1.5 days ' +
+      'long break of (36 hours)'
+  );
+
+  t.equal(
+    calcLongestStreak(
+      prepUniqueDays([
+        moment.utc('8/3/2015 2:00', 'M/D/YYYY H:mm').valueOf(),
+        moment.utc('9/11/2015 4:00', 'M/D/YYYY H:mm').valueOf(),
+        moment.utc('9/12/2015 1:00', 'M/D/YYYY H:mm').valueOf(),
+        moment.utc('9/12/2015 1:00', 'M/D/YYYY H:mm').valueOf(),
+        moment.utc('9/12/2015 2:00', 'M/D/YYYY H:mm').valueOf(),
+        moment.utc('9/12/2015 3:00', 'M/D/YYYY H:mm').valueOf(),
+        moment.utc('9/13/2015 4:00', 'M/D/YYYY H:mm').valueOf(),
+        moment.utc('9/14/2015 5:00', 'M/D/YYYY H:mm').valueOf(),
+        moment.utc(moment.utc().subtract(2, 'days')).valueOf(),
+        moment.utc(moment.utc().subtract(1, 'days')).valueOf(),
+        moment.utc().valueOf()
+      ])
+    ),
+    4,
+    'should return 4 when the longest streak consist of ' +
+      'several same day timestamps'
+  );
+
+  t.equal(
+    calcLongestStreak(
+      prepUniqueDays([
+        moment.utc('8/3/2015 2:00', 'M/D/YYYY H:mm').valueOf(),
+        moment.utc('9/11/2015 4:00', 'M/D/YYYY H:mm').valueOf(),
+        moment.utc('9/12/2015 1:00', 'M/D/YYYY H:mm').valueOf(),
+        moment.utc('9/13/2015 4:00', 'M/D/YYYY H:mm').valueOf(),
+        moment.utc('9/14/2015 5:00', 'M/D/YYYY H:mm').valueOf(),
+        moment.utc('10/11/2015 4:00', 'M/D/YYYY H:mm').valueOf(),
+        moment.utc('10/12/2015 1:00', 'M/D/YYYY H:mm').valueOf(),
+        moment.utc('10/13/2015 4:00', 'M/D/YYYY H:mm').valueOf(),
+        moment.utc('10/14/2015 5:00', 'M/D/YYYY H:mm').valueOf()
+      ])
+    ),
+    4,
+    'should return 4 when there are several longest streaks (same length)'
+  );
+
+  let cals = [];
+  const n = 100;
+  for (var i = 0; i < n; i++) {
+    cals.push(moment.utc(moment.utc().subtract(i, 'days')).valueOf());
+  }
+
+  t.equal(
+    calcLongestStreak(prepUniqueDays(cals)),
+    n,
+    'should return correct longest streak when there is a very long period'
+  );
+
+  t.equal(
+    calcLongestStreak(
+      prepUniqueDays([
+        moment.utc(moment.utc().subtract(1, 'days')).valueOf(),
+        moment.utc(moment.utc().subtract(1, 'hours')).valueOf()
+      ])
+    ),
+    2,
+    'should return correct longest streak in default timezone ' +
+      'UTC given `undefined` timezone'
+  );
+
+  t.equal(
+    calcLongestStreak(
+      prepUniqueDays([
+        moment.utc('9/11/2015 4:00', 'M/D/YYYY H:mm').valueOf(),
+        moment.utc('9/12/2015 2:00', 'M/D/YYYY H:mm').valueOf(),
+        moment.utc('9/13/2015 3:00', 'M/D/YYYY H:mm').valueOf(),
+        moment.utc('9/14/2015 1:00', 'M/D/YYYY H:mm').valueOf()
+      ]), PST
+    ),
+    4,
+    'should return 4 when there is the only one more-than-one-days-long ' +
+      'streak available given PST'
+  );
+
+  t.equal(
+    calcLongestStreak(
+      prepUniqueDays([
+        moment.utc('9/11/2015 23:00', 'M/D/YYYY H:mm').valueOf(),
+        moment.utc('9/12/2015 2:00', 'M/D/YYYY H:mm').valueOf(),
+        moment.utc('9/13/2015 2:00', 'M/D/YYYY H:mm').valueOf(),
+        moment.utc('9/14/2015 6:00', 'M/D/YYYY H:mm').valueOf()
+      ], PST), PST
+    ),
+    3,
+    'should return 3 when longest streak is 3 in PST ' +
+      '(but would be different in default timezone UTC)'
+  );
+
+  t.equal(
+    calcLongestStreak(
+      prepUniqueDays([
+        1453174506164, 1453175436725, 1453252466853, 1453294968225,
+        1453383782844, 1453431903117, 1453471373080, 1453594733026,
+        1453645014058, 1453746762747, 1453747659197, 1453748029416,
+        1453818029213, 1453951796007, 1453988570615, 1454069704441,
+        1454203673979, 1454294055498, 1454333545125, 1454415163903,
+        1454519128123, moment.tz(PST).valueOf()
+      ], PST),
+      PST
+    ),
+    17,
+    'should return 17 when there is no break in PST ' +
+      '(but would be break in UTC) and it is current'
+  );
+
+  t.equal(
+    calcLongestStreak(
+      prepUniqueDays([
+        1453174506164, 1453175436725, 1453252466853, 1453294968225,
+        1453383782844, 1453431903117, 1453471373080, 1453594733026,
+        1453645014058, 1453746762747, 1453747659197, 1453748029416,
+        1453818029213, 1453951796007, 1453988570615, 1454069704441,
+        1454203673979, 1454294055498, 1454333545125, 1454415163903,
+        1454519128123, moment.utc().valueOf()
+      ])
+    ),
+    4,
+    'should return 4 when there is a break in UTC (but no break in PST)'
+  );
+});
+
+test.onFinish(() => {
+  clock.restore();
+});
diff --git a/test/server/utils/date-utils-test.js b/test/server/utils/date-utils-test.js
deleted file mode 100644
index ad3ec46fea..0000000000
--- a/test/server/utils/date-utils-test.js
+++ /dev/null
@@ -1,45 +0,0 @@
-import moment from 'moment-timezone';
-
-import { dayCount } from '../../../server/utils/date-utils';
-
-let test = require('tape');
-const PST = 'America/Los_Angeles';
-
-test('Day count between two epochs (inclusive) calculation', function (t) {
-  t.plan(7);
-
-  t.equal(dayCount([
-    moment.utc("8/3/2015 3:00", "M/D/YYYY H:mm").valueOf(),
-    moment.utc("8/3/2015 2:00", "M/D/YYYY H:mm").valueOf()
-  ]), 1, "should return 1 day given epochs of the same day");
-
-  t.equal(dayCount([
-    moment.utc("8/3/2015 2:00", "M/D/YYYY H:mm").valueOf(),
-    moment.utc("8/3/2015 2:00", "M/D/YYYY H:mm").valueOf()
-  ]), 1, "should return 1 day given same epochs");
-
-  t.equal(dayCount([
-    moment.utc("8/4/2015 2:00", "M/D/YYYY H:mm").valueOf(),
-    moment.utc("8/3/2015 2:00", "M/D/YYYY H:mm").valueOf()
-  ]), 2, "should return 2 days when there is a 24 hours difference between given dates");
-
-  t.equal(dayCount([
-    moment.utc("8/4/2015 1:00", "M/D/YYYY H:mm").valueOf(),
-    moment.utc("8/3/2015 23:00", "M/D/YYYY H:mm").valueOf()
-  ]), 2, "should return 2 days when the diff is less than 24h but days are different in UTC");
-
-  t.equal(dayCount([
-    moment.utc("8/4/2015 1:00", "M/D/YYYY H:mm").valueOf(),
-    moment.utc("8/3/2015 23:00", "M/D/YYYY H:mm").valueOf()
-  ], PST), 1, "should return 1 day when the diff is less than 24h and days are different in UTC, but given PST");
-
-  t.equal(dayCount([
-    moment.utc("10/27/2015 1:00", "M/D/YYYY H:mm").valueOf(),
-    moment.utc("5/12/1982 1:00", "M/D/YYYY H:mm").valueOf()
-  ]), 12222, "should return correct count when there is very big period");
-
-  t.equal(dayCount([
-    moment.utc("8/4/2015 2:00", "M/D/YYYY H:mm").valueOf(),
-    moment.utc("8/3/2015 2:00", "M/D/YYYY H:mm").valueOf()
-  ], undefined), 2, "should return 2 days when there is a 24 hours difference between dates given 'undefined' timezone");
-});
diff --git a/test/server/utils/user-stats-test.js b/test/server/utils/user-stats-test.js
deleted file mode 100644
index fc64adf7f7..0000000000
--- a/test/server/utils/user-stats-test.js
+++ /dev/null
@@ -1,262 +0,0 @@
-import moment from 'moment-timezone';
-import sinon from 'sinon';
-
-import {
-  prepUniqueDays,
-  calcCurrentStreak,
-  calcLongestStreak
-} from '../../../server/utils/user-stats';
-
-let test = require('tape');
-let clock = sinon.useFakeTimers(1454526000000); // setting now to 2016-02-03T11:00:00 (PST)
-const PST = 'America/Los_Angeles';
-
-test('Prepare calendar items', function (t) {
-
-  t.plan(5);
-
-  t.deepEqual(prepUniqueDays([
-    moment.utc("8/3/2015 2:00", "M/D/YYYY H:mm").valueOf(),
-    moment.utc("8/3/2015 14:00", "M/D/YYYY H:mm").valueOf(),
-    moment.utc("8/3/2015 20:00", "M/D/YYYY H:mm").valueOf()
-  ]), [1438560000000], "should return correct epoch when all entries fall into one day in UTC");
-
-  t.deepEqual(prepUniqueDays([
-    moment.utc("8/3/2015 2:00", "M/D/YYYY H:mm").valueOf(),
-    moment.utc("8/3/2015 2:00", "M/D/YYYY H:mm").valueOf()
-  ]), [1438560000000], "should return correct epoch when given two identical dates");
-
-
-  t.deepEqual(prepUniqueDays([
-    moment.utc("8/3/2015 2:00", "M/D/YYYY H:mm").valueOf(), // 8/2/2015 in America/Los_Angeles
-    moment.utc("8/3/2015 14:00", "M/D/YYYY H:mm").valueOf(),
-    moment.utc("8/3/2015 20:00", "M/D/YYYY H:mm").valueOf()
-  ], PST), [1438498800000, 1438585200000], "should return 2 epochs when dates fall into two days in PST");
-
-  t.deepEqual(prepUniqueDays([
-    moment.utc("8/1/2015 2:00", "M/D/YYYY H:mm").valueOf(),
-    moment.utc("3/3/2015 14:00", "M/D/YYYY H:mm").valueOf(),
-    moment.utc("9/30/2014 20:00", "M/D/YYYY H:mm").valueOf()
-  ]), [1412035200000, 1425340800000, 1438387200000], "should return 3 epochs when dates fall into three days");
-
-  t.deepEqual(prepUniqueDays([
-    1438387200000, 1425340800000, 1412035200000
-  ]), [1412035200000, 1425340800000, 1438387200000], "should return same but sorted array if all input dates are start of day");
-
-});
-
-test('Current streak calculation', function (t) {
-
-  t.plan(11);
-
-  t.equal(calcCurrentStreak(
-    prepUniqueDays([
-      moment.utc(moment.utc().subtract(1, 'hours')).valueOf()
-    ])), 1, "should return 1 day when today one challenge was completed");
-
-  t.equal(calcCurrentStreak(
-    prepUniqueDays([
-      moment.utc(moment.utc().subtract(1, 'hours')).valueOf(),
-      moment.utc(moment.utc().subtract(1, 'hours')).valueOf()
-    ])), 1, "should return 1 day when today more than one challenge was completed");
-
-  t.equal(calcCurrentStreak(
-    prepUniqueDays([
-      moment.utc("9/11/2015 4:00", "M/D/YYYY H:mm").valueOf()
-    ])), 0, "should return 0 day when today 0 challenges were completed");
-
-  t.equal(calcCurrentStreak(
-    prepUniqueDays([
-      moment.utc(moment.utc().subtract(1, 'days')).valueOf(),
-      moment.utc(moment.utc().subtract(1, 'hours')).valueOf()
-    ])), 2, "should return 2 days when today and yesterday challenges were completed");
-
-  t.equal(calcCurrentStreak(
-    prepUniqueDays([
-      moment.utc("8/3/2015 2:00", "M/D/YYYY H:mm").valueOf(),
-      moment.utc("9/11/2015 4:00", "M/D/YYYY H:mm").valueOf(),
-      moment.utc("9/12/2015 1:00", "M/D/YYYY H:mm").valueOf(),
-      moment.utc("9/12/2015 1:00", "M/D/YYYY H:mm").valueOf(),
-      moment.utc("9/12/2015 2:00", "M/D/YYYY H:mm").valueOf(),
-      moment.utc("9/12/2015 3:00", "M/D/YYYY H:mm").valueOf(),
-      moment.utc("9/13/2015 4:00", "M/D/YYYY H:mm").valueOf(),
-      moment.utc("9/14/2015 5:00", "M/D/YYYY H:mm").valueOf(),
-      moment.utc(moment.utc().subtract(2, 'days')).valueOf(),
-      moment.utc(moment.utc().subtract(1, 'days')).valueOf(),
-      moment.utc(moment.utc().subtract(1, 'hours')).valueOf()
-    ])), 3, "should return 3 when today and for two days before user was activity");
-
-  t.equal(calcCurrentStreak(
-    prepUniqueDays([
-      moment.utc(moment.utc().subtract(47, 'hours')).valueOf(),
-      moment.utc(moment.utc().subtract(11, 'hours')).valueOf()
-    ])), 1, "should return 1 when there is 1.5 days long break and dates fall into two days separated by third");
-
-  t.equal(calcCurrentStreak(
-    prepUniqueDays([
-      moment.utc(moment.utc().subtract(40, 'hours')).valueOf(),
-      moment.utc(moment.utc().subtract(1, 'hours')).valueOf()
-    ])), 2, "should return 2 when the break is more than 1.5 days but dates fall into two consecutive days");
-
-  t.equal(calcCurrentStreak(
-    prepUniqueDays([
-      moment.utc(moment.utc().subtract(1, 'hours')).valueOf(),
-      moment.utc(moment.utc().subtract(1, 'hours')).valueOf()
-    ]), undefined), 1, "should return correct count in default timezone UTC given 'undefined' timezone");
-
-  t.equal(calcCurrentStreak(
-    prepUniqueDays([
-      moment.utc(moment.utc().subtract(1, 'days')).valueOf(),
-      moment.utc(moment.utc().subtract(1, 'hours')).valueOf()
-    ], PST), PST), 2, "should return 2 days when today and yesterday challenges were completed given PST");
-
-  t.equal(calcCurrentStreak(
-    prepUniqueDays([
-      1453174506164, 1453175436725, 1453252466853, 1453294968225, 1453383782844,
-      1453431903117, 1453471373080, 1453594733026, 1453645014058, 1453746762747,
-      1453747659197, 1453748029416, 1453818029213, 1453951796007, 1453988570615,
-      1454069704441, 1454203673979, 1454294055498, 1454333545125, 1454415163903,
-      1454519128123, moment.tz(PST).valueOf()
-    ], PST), PST), 17, "should return 17 when there is no break in given timezone (but would be the break if in UTC)");
-
-  t.equal(calcCurrentStreak(
-    prepUniqueDays([
-      1453174506164, 1453175436725, 1453252466853, 1453294968225, 1453383782844,
-      1453431903117, 1453471373080, 1453594733026, 1453645014058, 1453746762747,
-      1453747659197, 1453748029416, 1453818029213, 1453951796007, 1453988570615,
-      1454069704441, 1454203673979, 1454294055498, 1454333545125, 1454415163903,
-      1454519128123, moment.utc().valueOf()
-    ])), 4, "should return 4 when there is a break in UTC (but would be no break in PST)");
-
-});
-
-test('Longest streak calculation', function (t) {
-  t.plan(14);
-
-  t.equal(calcLongestStreak(
-    prepUniqueDays([
-      moment.utc("9/12/2015 4:00", "M/D/YYYY H:mm").valueOf()
-    ])), 1, "should return 1 when there is the only one one-day-long streak available");
-
-  t.equal(calcLongestStreak(
-    prepUniqueDays([
-      moment.utc("9/11/2015 4:00", "M/D/YYYY H:mm").valueOf(),
-      moment.utc("9/12/2015 2:00", "M/D/YYYY H:mm").valueOf(),
-      moment.utc("9/13/2015 3:00", "M/D/YYYY H:mm").valueOf(),
-      moment.utc("9/14/2015 1:00", "M/D/YYYY H:mm").valueOf()
-    ])), 4, "should return 4 when there is the only one more-than-one-days-long streak available");
-
-  t.equal(calcLongestStreak(
-    prepUniqueDays([
-      moment.utc(moment.utc().subtract(1, 'hours')).valueOf()
-    ])), 1, "should return 1 when there is only one one-day-long streak and it is today");
-
-  t.equal(calcLongestStreak(
-    prepUniqueDays([
-      moment.utc(moment.utc().subtract(1, 'days')).valueOf(),
-      moment.utc(moment.utc().subtract(1, 'hours')).valueOf()
-    ])), 2, "should return 2 when yesterday and today makes longest streak");
-
-  t.equal(calcLongestStreak(
-    prepUniqueDays([
-      moment.utc("8/3/2015 2:00", "M/D/YYYY H:mm").valueOf(),
-      moment.utc("9/11/2015 4:00", "M/D/YYYY H:mm").valueOf(),
-      moment.utc("9/12/2015 2:00", "M/D/YYYY H:mm").valueOf(),
-      moment.utc("10/4/2015 1:00", "M/D/YYYY H:mm").valueOf(),
-      moment.utc("10/5/2015 5:00", "M/D/YYYY H:mm").valueOf(),
-      moment.utc("10/6/2015 4:00", "M/D/YYYY H:mm").valueOf(),
-      moment.utc("10/7/2015 5:00", "M/D/YYYY H:mm").valueOf(),
-      moment.utc("11/3/2015 2:00", "M/D/YYYY H:mm").valueOf()
-    ])), 4, "should return 4 when there is a month long break");
-
-  t.equal(calcLongestStreak(
-    prepUniqueDays([
-      moment.utc("8/3/2015 2:00", "M/D/YYYY H:mm").valueOf(),
-      moment.utc("9/11/2015 4:00", "M/D/YYYY H:mm").valueOf(),
-      moment.utc("9/12/2015 15:30", "M/D/YYYY H:mm").valueOf(),
-      moment.utc(moment.utc("9/12/2015 15:30", "M/D/YYYY H:mm").add(37, 'hours')).valueOf(),
-      moment.utc("9/14/2015 22:00", "M/D/YYYY H:mm").valueOf(),
-      moment.utc("9/15/2015 4:00", "M/D/YYYY H:mm").valueOf(),
-      moment.utc("10/3/2015 2:00", "M/D/YYYY H:mm").valueOf()
-    ])), 2, "should return 2 when there is a more than 1.5 days long break of (36 hours)");
-
-  t.equal(calcLongestStreak(
-    prepUniqueDays([
-      moment.utc("8/3/2015 2:00", "M/D/YYYY H:mm").valueOf(),
-      moment.utc("9/11/2015 4:00", "M/D/YYYY H:mm").valueOf(),
-      moment.utc("9/12/2015 1:00", "M/D/YYYY H:mm").valueOf(),
-      moment.utc("9/12/2015 1:00", "M/D/YYYY H:mm").valueOf(),
-      moment.utc("9/12/2015 2:00", "M/D/YYYY H:mm").valueOf(),
-      moment.utc("9/12/2015 3:00", "M/D/YYYY H:mm").valueOf(),
-      moment.utc("9/13/2015 4:00", "M/D/YYYY H:mm").valueOf(),
-      moment.utc("9/14/2015 5:00", "M/D/YYYY H:mm").valueOf(),
-      moment.utc(moment.utc().subtract(2, 'days')).valueOf(),
-      moment.utc(moment.utc().subtract(1, 'days')).valueOf(),
-      moment.utc().valueOf()
-    ])), 4, "should return 4 when the longest streak consist of several same day timestamps");
-
-  t.equal(calcLongestStreak(
-    prepUniqueDays([
-      moment.utc("8/3/2015 2:00", "M/D/YYYY H:mm").valueOf(),
-      moment.utc("9/11/2015 4:00", "M/D/YYYY H:mm").valueOf(),
-      moment.utc("9/12/2015 1:00", "M/D/YYYY H:mm").valueOf(),
-      moment.utc("9/13/2015 4:00", "M/D/YYYY H:mm").valueOf(),
-      moment.utc("9/14/2015 5:00", "M/D/YYYY H:mm").valueOf(),
-      moment.utc("10/11/2015 4:00", "M/D/YYYY H:mm").valueOf(),
-      moment.utc("10/12/2015 1:00", "M/D/YYYY H:mm").valueOf(),
-      moment.utc("10/13/2015 4:00", "M/D/YYYY H:mm").valueOf(),
-      moment.utc("10/14/2015 5:00", "M/D/YYYY H:mm").valueOf()
-    ])), 4, "should return 4 when there are several longest streaks (same length)");
-
-  let cals = [];
-  const n = 100;
-  for (var i = 0; i < n; i++) {
-    cals.push(moment.utc(moment.utc().subtract(i, 'days')).valueOf());
-  }
-  t.equal(calcLongestStreak(prepUniqueDays(cals)), n, "should return correct longest streak when there is a very long period");
-
-  t.equal(calcLongestStreak(
-    prepUniqueDays([
-      moment.utc(moment.utc().subtract(1, 'days')).valueOf(),
-      moment.utc(moment.utc().subtract(1, 'hours')).valueOf()
-    ]), undefined), 2, "should return correct longest streak in default timezone UTC given 'undefined' timezone");
-
-  t.equal(calcLongestStreak(
-    prepUniqueDays([
-      moment.utc("9/11/2015 4:00", "M/D/YYYY H:mm").valueOf(),
-      moment.utc("9/12/2015 2:00", "M/D/YYYY H:mm").valueOf(),
-      moment.utc("9/13/2015 3:00", "M/D/YYYY H:mm").valueOf(),
-      moment.utc("9/14/2015 1:00", "M/D/YYYY H:mm").valueOf()
-    ]), PST), 4, "should return 4 when there is the only one more-than-one-days-long streak available given PST");
-
-  t.equal(calcLongestStreak(
-    prepUniqueDays([
-      moment.utc("9/11/2015 23:00", "M/D/YYYY H:mm").valueOf(),
-      moment.utc("9/12/2015 2:00", "M/D/YYYY H:mm").valueOf(),
-      moment.utc("9/13/2015 2:00", "M/D/YYYY H:mm").valueOf(),
-      moment.utc("9/14/2015 6:00", "M/D/YYYY H:mm").valueOf()
-    ], PST), PST), 3, "should return 3 when longest streak is 3 in PST (but would be different in default timezone UTC)");
-
-  t.equal(calcLongestStreak(
-    prepUniqueDays([
-      1453174506164, 1453175436725, 1453252466853, 1453294968225, 1453383782844,
-      1453431903117, 1453471373080, 1453594733026, 1453645014058, 1453746762747,
-      1453747659197, 1453748029416, 1453818029213, 1453951796007, 1453988570615,
-      1454069704441, 1454203673979, 1454294055498, 1454333545125, 1454415163903,
-      1454519128123, moment.tz(PST).valueOf()
-    ], PST), PST), 17, "should return 17 when there is no break in PST (but would be break in UTC) and it is current");
-
-  t.equal(calcLongestStreak(
-    prepUniqueDays([
-      1453174506164, 1453175436725, 1453252466853, 1453294968225, 1453383782844,
-      1453431903117, 1453471373080, 1453594733026, 1453645014058, 1453746762747,
-      1453747659197, 1453748029416, 1453818029213, 1453951796007, 1453988570615,
-      1454069704441, 1454203673979, 1454294055498, 1454333545125, 1454415163903,
-      1454519128123, moment.utc().valueOf()
-    ])), 4, "should return 4 when there is a break in UTC (but no break in PST)");
-
-});
-
-test.onFinish(() => {
-  clock.restore();
-});