diff --git a/CHANGELOG.md b/CHANGELOG.md
index 0663bfb..8a607c3 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -5,6 +5,8 @@ All notable changes to this project will be documented in this file.
 The format is based on [Keep a Changelog](http://keepachangelog.com/) and this project adheres to [Semantic Versioning](http://semver.org/).
 
 ## [Unreleased]
+### Changed
+- Swaps out Moment.js for date-fns to improve blame annotation performance and to reduce the GitLen bundle size (saves ~400kb)
 
 ## [5.6.2] - 2017-10-11
 ### Fixed
diff --git a/package-lock.json b/package-lock.json
index 1178c50..f1d937e 100644
--- a/package-lock.json
+++ b/package-lock.json
@@ -375,6 +375,11 @@
                 }
             }
         },
+        "date-fns": {
+            "version": "1.29.0",
+            "resolved": "https://registry.npmjs.org/date-fns/-/date-fns-1.29.0.tgz",
+            "integrity": "sha512-lbTXWZ6M20cWH8N9S6afb0SBm6tMk+uUg6z3MqHPKE9atmsY3kJkTm8vKe93izJ2B2+q5MV990sM2CHgtAZaOw=="
+        },
         "dateformat": {
             "version": "2.2.0",
             "resolved": "https://registry.npmjs.org/dateformat/-/dateformat-2.2.0.tgz",
@@ -1841,11 +1846,6 @@
                 }
             }
         },
-        "moment": {
-            "version": "2.19.1",
-            "resolved": "https://registry.npmjs.org/moment/-/moment-2.19.1.tgz",
-            "integrity": "sha1-VtoaLRy/AdOLfhr8McELz6GSkWc="
-        },
         "ms": {
             "version": "2.0.0",
             "resolved": "https://registry.npmjs.org/ms/-/ms-2.0.0.tgz",
diff --git a/package.json b/package.json
index 2ee4b04..2635131 100644
--- a/package.json
+++ b/package.json
@@ -1998,13 +1998,13 @@
     "dependencies": {
         "applicationinsights": "0.21.0",
         "copy-paste": "1.3.0",
+        "date-fns": "1.29.0",
         "iconv-lite": "0.4.19",
         "ignore": "3.3.5",
         "lodash.debounce": "4.0.8",
         "lodash.escaperegexp": "4.1.2",
         "lodash.isequal": "4.5.0",
         "lodash.once": "4.1.1",
-        "moment": "2.19.1",
         "spawn-rx": "2.0.12",
         "tmp": "0.0.33"
     },
diff --git a/src/system/date.ts b/src/system/date.ts
index 730c996..a5f8124 100644
--- a/src/system/date.ts
+++ b/src/system/date.ts
@@ -1,9 +1,121 @@
 'use strict';
-import * as moment from 'moment';
+import { distanceInWordsToNow as _fromNow, format as _format } from 'date-fns';
+import * as en from 'date-fns/locale/en';
 
 const MillisecondsPerMinute = 60000; // 60 * 1000
 const MillisecondsPerDay = 86400000; // 24 * 60 * 60 * 1000
 
+// Taken from https://github.com/date-fns/date-fns/blob/601bc8e5708cbaebee5389bdaf51c2b4b33b73c4/src/locale/en/build_distance_in_words_locale/index.js
+function buildDistanceInWordsLocale() {
+    const distanceInWordsLocale: { [key: string]: string | { one: string, other: string } } = {
+        lessThanXSeconds: {
+            one: 'less than a second',
+            other: 'less than {{count}} seconds'
+        },
+
+        xSeconds: {
+            one: '1 second',
+            other: '{{count}} seconds'
+        },
+
+        halfAMinute: 'half a minute',
+
+        lessThanXMinutes: {
+            one: 'a few seconds',
+            other: 'less than {{count}} minutes'
+        },
+
+        xMinutes: {
+            one: 'a minute',
+            other: '{{count}} minutes'
+        },
+
+        aboutXHours: {
+            one: 'an hour',
+            other: '{{count}} hours'
+        },
+
+        xHours: {
+            one: 'an hour',
+            other: '{{count}} hours'
+        },
+
+        xDays: {
+            one: 'a day',
+            other: '{{count}} days'
+        },
+
+        aboutXMonths: {
+            one: 'a month',
+            other: '{{count}} months'
+        },
+
+        xMonths: {
+            one: 'a month',
+            other: '{{count}} months'
+        },
+
+        aboutXYears: {
+            one: 'a year',
+            other: '{{count}} years'
+        },
+
+        xYears: {
+            one: 'a year',
+            other: '{{count}} years'
+        },
+
+        overXYears: {
+            one: 'a year',
+            other: '{{count}} years'
+        },
+
+        almostXYears: {
+            one: 'a year',
+            other: '{{count}} years'
+        }
+    };
+
+    function localize(token: string, count: number, options: any) {
+        options = options || {};
+
+        const result = distanceInWordsLocale[token];
+
+        let value: string;
+        if (typeof result === 'string') {
+            value = result;
+        }
+        else {
+            if (count === 12 && token === 'xMonths') {
+                token = 'aboutXYears';
+                count = 1;
+            }
+
+            if (count === 1) {
+                value = result.one;
+            }
+            else {
+                value = result.other.replace('{{count}}', count.toString());
+            }
+        }
+
+        if (!options.addSuffix) return value;
+
+        if (options.comparison > 0) return 'in ' + value;
+
+        return value + ' ago';
+    }
+
+    return {
+        localize: localize
+    };
+}
+
+// Monkey patch the locale to customize the wording
+(en as any).distanceInWords = buildDistanceInWordsLocale();
+
+const formatterOptions = { addSuffix: true, locale: en };
+
 export namespace Dates {
 
     export interface IDateFormatter {
@@ -28,6 +140,9 @@ export namespace Dates {
     }
 
     export function toFormatter(date: Date): IDateFormatter {
-        return moment(date);
+        return {
+            fromNow: () => _fromNow(date, formatterOptions),
+            format: (format: string) => _format(date, format)
+        };
     }
 }
\ No newline at end of file