diff --git a/app/assets/javascripts/lib/utils/datetime/timeago_utility.js b/app/assets/javascripts/lib/utils/datetime/timeago_utility.js
index f8ef0b20cada65700ea1d11373bdae2c2cecfe62..9bdc78cf2156de60a343fedf071185c81c932fb7 100644
--- a/app/assets/javascripts/lib/utils/datetime/timeago_utility.js
+++ b/app/assets/javascripts/lib/utils/datetime/timeago_utility.js
@@ -1,6 +1,7 @@
 import * as timeago from 'timeago.js';
 import { diffSec } from 'timeago.js/lib/utils/date';
 import { newDate } from '~/lib/utils/datetime/date_calculation_utility';
+import { formatDate } from '~/lib/utils/datetime/date_format_utility';
 import {
   DEFAULT_DATE_TIME_FORMAT,
   DATE_ONLY_FORMAT,
@@ -202,8 +203,19 @@ export const localTimeAgo = (elements, updateTooltip = true) => {
 
   function addTimeAgoTooltip() {
     elements.forEach((el) => {
-      // Recreate with custom template
-      el.setAttribute('title', localeDateFormat.asDateTimeFull.format(newDate(el.dateTime)));
+      const customFormat = el.dataset.tooltipFormat;
+      const dateTime = newDate(el.dateTime);
+      let title = null;
+
+      if (customFormat && localeDateFormat[customFormat]) {
+        title = localeDateFormat[customFormat].format(dateTime);
+      } else if (customFormat) {
+        title = formatDate(dateTime, customFormat);
+      } else {
+        title = localeDateFormat.asDateTimeFull.format(dateTime);
+      }
+
+      el.setAttribute('title', title);
     });
   }
 
diff --git a/app/helpers/application_helper.rb b/app/helpers/application_helper.rb
index fca4359ec04f3d2fc02f87846fd5119a5ae19ec7..fa793e9722a6ea4deb5182b452a3cbaa655d3d03 100644
--- a/app/helpers/application_helper.rb
+++ b/app/helpers/application_helper.rb
@@ -198,22 +198,32 @@ def registry_config
   # `html_class` argument is provided.
   #
   # Returns an HTML-safe String
-  def time_ago_with_tooltip(time, placement: 'top', html_class: '', short_format: false)
+  def time_ago_with_tooltip(time, placement: 'top', html_class: '', short_format: false, tooltip_format: :timeago_tooltip)
     return "" if time.nil?
 
     css_classes = [short_format ? 'js-short-timeago' : 'js-timeago']
     css_classes << html_class unless html_class.blank?
 
+    formatted_time = case tooltip_format
+                     when :timeago_tooltip
+                       l(time.to_time.in_time_zone, format: tooltip_format)
+                     when Symbol
+                       time.to_time.getutc.iso8601
+                     else
+                       time.to_time.in_time_zone.strftime(tooltip_format)
+                     end
+
     content_tag :time, l(time, format: "%b %d, %Y"),
       class: css_classes.join(' '),
-      title: l(time.to_time.in_time_zone, format: :timeago_tooltip),
+      title: formatted_time,
       datetime: time.to_time.getutc.iso8601,
       tabindex: '0',
-      aria: { label: l(time.to_time.in_time_zone, format: :timeago_tooltip) },
+      aria: { label: formatted_time },
       data: {
         toggle: 'tooltip',
         placement: placement,
-        container: 'body'
+        container: 'body',
+        tooltip_format: (tooltip_format != :timeago_tooltip ? tooltip_format.to_s : nil)
       }
   end
 
diff --git a/app/views/projects/commits/_committer.html.haml b/app/views/projects/commits/_committer.html.haml
index 86574a18554874e3b8b6da52e57f616644f53744..a900a99c6b506dd5f46d80e573e2e844ae707020 100644
--- a/app/views/projects/commits/_committer.html.haml
+++ b/app/views/projects/commits/_committer.html.haml
@@ -1,9 +1,9 @@
 .committer.gl-text-sm
   - commit_author_link = commit_author_link(commit, avatar: false, size: 24)
-  - commit_authored_timeago = time_ago_with_tooltip(commit.authored_date, placement: 'bottom')
+  - commit_authored_timeago = time_ago_with_tooltip(commit.authored_date, placement: 'bottom', tooltip_format: 'mmm d, yyyy h:MMtt Z')
   - if commit.different_committer? && commit.committer
     - commit_committer_link = commit_committer_link(commit)
-    - commit_committer_timeago = time_ago_with_tooltip(commit.committed_date, placement: 'bottom')
+    - commit_committer_timeago = time_ago_with_tooltip(commit.committed_date, placement: 'bottom', tooltip_format: 'mmm d, yyyy h:MMtt Z')
     - commit_committer_avatar = commit_committer_avatar(commit.committer, size: 16, has_tooltip: false)
     - commit_text = _('%{commit_author_link} authored %{commit_authored_timeago} and %{commit_committer_avatar} %{commit_committer_link} committed %{commit_committer_timeago}') % { commit_author_link: commit_author_link, commit_authored_timeago: commit_authored_timeago, commit_committer_avatar: commit_committer_avatar, commit_committer_link: commit_committer_link, commit_committer_timeago: commit_committer_timeago }
   - else
diff --git a/spec/frontend/lib/utils/datetime/timeago_utility_spec.js b/spec/frontend/lib/utils/datetime/timeago_utility_spec.js
index b3b088fce13e36e407d51607466e6bba0e46df49..33159a7570a52500d8e7d7d44e1eb8eb1aba4108 100644
--- a/spec/frontend/lib/utils/datetime/timeago_utility_spec.js
+++ b/spec/frontend/lib/utils/datetime/timeago_utility_spec.js
@@ -229,5 +229,40 @@ describe('TimeAgo utils', () => {
         expect(element.innerText).toBe(text);
       });
     });
+
+    describe('with custom tooltip format', () => {
+      beforeEach(() => {
+        window.gon = { time_display_relative: false };
+      });
+
+      it('uses formatDate when data-tooltip-format is a custom string', () => {
+        const element = document.querySelector('time');
+        element.dataset.tooltipFormat = 'mmm d, yyyy h:MMtt Z';
+
+        localTimeAgo([element]);
+        jest.runAllTimers();
+
+        expect(element.getAttribute('title')).toBe('Feb 18, 2020 10:22pm UTC');
+      });
+
+      it('uses localeDateFormat when data-tooltip-format matches a known format key', () => {
+        const element = document.querySelector('time');
+        element.dataset.tooltipFormat = 'asDateTimeFull';
+
+        localTimeAgo([element]);
+        jest.runAllTimers();
+
+        expect(element.getAttribute('title')).toBe('February 18, 2020 at 22:22:32 GMT');
+      });
+
+      it('uses default asDateTimeFull when no data-tooltip-format is set', () => {
+        const element = document.querySelector('time');
+
+        localTimeAgo([element]);
+        jest.runAllTimers();
+
+        expect(element.getAttribute('title')).toBe('February 18, 2020 at 22:22:32 GMT');
+      });
+    });
   });
 });
diff --git a/spec/helpers/application_helper_spec.rb b/spec/helpers/application_helper_spec.rb
index f4f95f5bfc461b2191612f9fe5b84b5a66de04c9..735fd993ecff16a61e90c4beeed40b57b958ff16 100644
--- a/spec/helpers/application_helper_spec.rb
+++ b/spec/helpers/application_helper_spec.rb
@@ -180,6 +180,29 @@ def element(**arguments)
       expect(el).to eq('')
       expect(el.html_safe).to eq('')
     end
+
+    context 'with custom tooltip_format' do
+      it 'uses strftime format when tooltip_format is a string' do
+        timeago_element = element(tooltip_format: '%B %d, %Y at %I:%M%p')
+
+        expect(timeago_element.attr('title')).to eq('July 02, 2015 at 08:23AM')
+        expect(timeago_element.attr('data-tooltip-format')).to eq('%B %d, %Y at %I:%M%p')
+      end
+
+      it 'uses ISO8601 format when tooltip_format is a non-default symbol' do
+        timeago_element = element(tooltip_format: :custom_format)
+
+        expect(timeago_element.attr('title')).to eq('2015-07-02T08:23:00Z')
+        expect(timeago_element.attr('data-tooltip-format')).to eq('custom_format')
+      end
+
+      it 'does not set data-tooltip-format when using default :timeago_tooltip' do
+        timeago_element = element(tooltip_format: :timeago_tooltip)
+
+        expect(timeago_element.attr('title')).to eq('Jul 2, 2015 8:23am')
+        expect(timeago_element.attr('data-tooltip-format')).to be_nil
+      end
+    end
   end
 
   describe 'edited_time_ago_with_tooltip' do