diff --git a/app/helpers/application_formatters_helper.rb b/app/helpers/application_formatters_helper.rb
index 7415cb4d388..b9a2a70cfc7 100644
--- a/app/helpers/application_formatters_helper.rb
+++ b/app/helpers/application_formatters_helper.rb
@@ -82,4 +82,19 @@ def format_duration(total_seconds)
     hours = total_seconds / (60 * 60)
     format('%<hours>02dH%<minutes>02dM%<seconds>02dS', hours: hours, minutes: minutes, seconds: seconds)
   end
+
+  # Formats rich text fields for CSV export by stripping HTML tags and decoding HTML entities.
+  # Rich text fields are saved as HTML in the database (from WYSIWYG editors), so this helper
+  # converts them to plain text suitable for CSV files by removing HTML markup and decoding
+  # entities like &nbsp;, &amp;, etc.
+  #
+  # @param [String] text The rich text (HTML) to format
+  # @param [Boolean] preserve_newlines Whether to preserve paragraph/line breaks (default: true)
+  # @return [String] Plain text with HTML tags removed and entities decoded
+  def format_rich_text_for_csv(text)
+    return '' unless text
+
+    cleaned_text = text.gsub('</p>', "</p>\n").gsub('<br />', "<br />\n")
+    HTMLEntities.new.decode(ActionController::Base.helpers.strip_tags(cleaned_text)).strip
+  end
 end
diff --git a/app/helpers/course/statistics/aggregate_helper.rb b/app/helpers/course/statistics/aggregate_helper.rb
deleted file mode 100644
index 20f14fc20b5..00000000000
--- a/app/helpers/course/statistics/aggregate_helper.rb
+++ /dev/null
@@ -1,14 +0,0 @@
-# frozen_string_literal: true
-module Course::Statistics::AggregateHelper
-  # Convert time in seconds to HH:MM:SS format.
-  def seconds_to_str(total_seconds)
-    return '--:--:--' unless total_seconds
-
-    seconds = total_seconds % 60
-    minutes = (total_seconds / 60) % 60
-    hours = (total_seconds / (60 * 60)) % 24
-    days = total_seconds / (60 * 60 * 24)
-
-    format("%2d #{t('time.day')} %02d:%02d:%02d", days, hours, minutes, seconds)
-  end
-end
diff --git a/app/models/course/assessment/answer/forum_post_response.rb b/app/models/course/assessment/answer/forum_post_response.rb
index 1921cb2ce6e..25474184efd 100644
--- a/app/models/course/assessment/answer/forum_post_response.rb
+++ b/app/models/course/assessment/answer/forum_post_response.rb
@@ -77,8 +77,7 @@ def stripped_answer_to_array
   def readable_string_of(text)
     return nil unless text
 
-    cleaned_text = text.gsub('</p>', "</p>\n").gsub('<br />', "<br />\n").squish
-    ActionController::Base.helpers.strip_tags(cleaned_text)
+    ApplicationController.helpers.format_rich_text_for_csv(text).squish
   end
 
   def destroy_previous_selection
diff --git a/app/models/course/assessment/answer/multiple_response.rb b/app/models/course/assessment/answer/multiple_response.rb
index c0758e9ae68..975d69686e9 100644
--- a/app/models/course/assessment/answer/multiple_response.rb
+++ b/app/models/course/assessment/answer/multiple_response.rb
@@ -34,6 +34,6 @@ def compare_answer(other_answer)
   end
 
   def csv_download
-    ActionController::Base.helpers.strip_tags(options.map(&:option).join(';'))
+    ApplicationController.helpers.format_rich_text_for_csv(options.map(&:option).join(';'))
   end
 end
diff --git a/app/models/course/assessment/answer/rubric_based_response.rb b/app/models/course/assessment/answer/rubric_based_response.rb
index 5354ec5a74a..dcb4b17d38b 100644
--- a/app/models/course/assessment/answer/rubric_based_response.rb
+++ b/app/models/course/assessment/answer/rubric_based_response.rb
@@ -42,7 +42,7 @@ def grade_inline?
   end
 
   def csv_download
-    ActionController::Base.helpers.strip_tags(answer_text)
+    ApplicationController.helpers.format_rich_text_for_csv(answer_text)
   end
 
   def compare_answer(other_answer)
diff --git a/app/models/course/assessment/answer/text_response.rb b/app/models/course/assessment/answer/text_response.rb
index 29a8c70242b..e0c84b232f7 100644
--- a/app/models/course/assessment/answer/text_response.rb
+++ b/app/models/course/assessment/answer/text_response.rb
@@ -25,7 +25,7 @@ def download(dir)
   end
 
   def csv_download
-    ActionController::Base.helpers.strip_tags(answer_text)
+    ApplicationController.helpers.format_rich_text_for_csv(answer_text)
   end
 
   def download_answer(dir)
diff --git a/app/services/course/survey/survey_download_service.rb b/app/services/course/survey/survey_download_service.rb
index f6545c57215..a3f8c83d6b9 100644
--- a/app/services/course/survey/survey_download_service.rb
+++ b/app/services/course/survey/survey_download_service.rb
@@ -3,6 +3,7 @@
 
 class Course::Survey::SurveyDownloadService
   include TmpCleanupHelper
+  include ApplicationFormattersHelper
 
   def initialize(survey)
     @survey = survey
@@ -57,7 +58,7 @@ def generate_header(questions)
       I18n.t('course.surveys.survey_download_service.course_user_id'),
       I18n.t('course.surveys.survey_download_service.name'),
       I18n.t('course.surveys.survey_download_service.role')
-    ] + questions.map(&:description)
+    ] + questions.map { |q| format_rich_text_for_csv(q.description) }
   end
 
   def generate_row(response, questions)
diff --git a/app/views/course/statistics/aggregate/all_assessments.json.jbuilder b/app/views/course/statistics/aggregate/all_assessments.json.jbuilder
index 7356b08fa4b..9cf70793fa5 100644
--- a/app/views/course/statistics/aggregate/all_assessments.json.jbuilder
+++ b/app/views/course/statistics/aggregate/all_assessments.json.jbuilder
@@ -24,8 +24,8 @@ json.assessments @assessments do |assessment|
   json.averageGrade grade_stats ? grade_stats[0] : 0
   json.stdevGrade grade_stats ? grade_stats[1] : 0
 
-  json.averageTimeTaken seconds_to_str(duration_stats[0])
-  json.stdevTimeTaken seconds_to_str(duration_stats[1])
+  json.averageTimeTaken duration_stats[0]
+  json.stdevTimeTaken duration_stats[1]
 
   json.numSubmitted @num_submitted_students_hash[assessment.id] || 0
   json.numAttempted @num_attempted_students_hash[assessment.id] || 0
diff --git a/app/views/course/statistics/aggregate/all_staff.json.jbuilder b/app/views/course/statistics/aggregate/all_staff.json.jbuilder
index d863a04e577..35e4f2d4ef5 100644
--- a/app/views/course/statistics/aggregate/all_staff.json.jbuilder
+++ b/app/views/course/statistics/aggregate/all_staff.json.jbuilder
@@ -6,6 +6,6 @@ json.staff graded_staff do |staff|
   json.name staff.name
   json.numGraded staff.published_submissions.size
   json.numStudents staff.my_students.count
-  json.averageMarkingTime seconds_to_str(staff.average_marking_time)
-  json.stddev seconds_to_str(staff.marking_time_stddev)
+  json.averageMarkingTime staff.average_marking_time
+  json.stddev staff.marking_time_stddev
 end
diff --git a/client/app/bundles/course/assessment/pages/AssessmentStatistics/LiveFeedbackHistory/LiveFeedbackMessageHistory.tsx b/client/app/bundles/course/assessment/pages/AssessmentStatistics/LiveFeedbackHistory/LiveFeedbackMessageHistory.tsx
index 3f36c1b3225..ad3d7e0df71 100644
--- a/client/app/bundles/course/assessment/pages/AssessmentStatistics/LiveFeedbackHistory/LiveFeedbackMessageHistory.tsx
+++ b/client/app/bundles/course/assessment/pages/AssessmentStatistics/LiveFeedbackHistory/LiveFeedbackMessageHistory.tsx
@@ -10,7 +10,7 @@ import {
 } from 'course/assessment/submission/components/GetHelpChatPage/utils';
 import MarkdownText from 'course/assessment/submission/components/MarkdownText';
 import useTranslation from 'lib/hooks/useTranslation';
-import moment, { SHORT_DATE_TIME_FORMAT } from 'lib/moment';
+import { formatShortDateTime } from 'lib/moment';
 
 interface Props {
   messages: LiveFeedbackChatMessage[];
@@ -110,9 +110,7 @@ const LiveFeedbackMessageHistory: FC<Props> = (props) => {
             const message = messages[messageIndex];
             const isStudent = message.creatorId !== 0;
             const isError = message.isError;
-            const createdAt = moment(new Date(message.createdAt)).format(
-              SHORT_DATE_TIME_FORMAT,
-            );
+            const createdAt = formatShortDateTime(message.createdAt);
 
             return (
               <div
diff --git a/client/app/bundles/course/assessment/submission/reducers/liveFeedbackChats/index.ts b/client/app/bundles/course/assessment/submission/reducers/liveFeedbackChats/index.ts
index b9d5d09290d..13b547d174b 100644
--- a/client/app/bundles/course/assessment/submission/reducers/liveFeedbackChats/index.ts
+++ b/client/app/bundles/course/assessment/submission/reducers/liveFeedbackChats/index.ts
@@ -6,7 +6,7 @@ import {
 } from '@reduxjs/toolkit';
 import shuffle from 'lodash-es/shuffle';
 
-import moment, { SHORT_TIME_FORMAT } from 'lib/moment';
+import moment, { formatShortTime } from 'lib/moment';
 
 import {
   getLocalStorageValue,
@@ -138,9 +138,7 @@ export const liveFeedbackChatSlice = createSlice({
               new Date(a.createdAt).getTime() - new Date(b.createdAt).getTime(),
           )
           .map((message) => {
-            const createdAt = moment(new Date(message.createdAt)).format(
-              SHORT_TIME_FORMAT,
-            );
+            const createdAt = formatShortTime(new Date(message.createdAt));
             return {
               sender:
                 message.creatorId === 0
@@ -267,7 +265,7 @@ export const liveFeedbackChatSlice = createSlice({
       const { answerId, message } = action.payload;
       const liveFeedbackChats =
         state.liveFeedbackChatPerAnswer.entities[answerId];
-      const currentTime = moment(new Date()).format(SHORT_TIME_FORMAT);
+      const currentTime = formatShortTime(new Date());
 
       if (liveFeedbackChats) {
         const changes: Partial<LiveFeedbackChatData> = {
@@ -342,7 +340,7 @@ export const liveFeedbackChatSlice = createSlice({
               {
                 sender: ChatSender.codaveri,
                 message: overallContent,
-                createdAt: moment(new Date()).format(SHORT_TIME_FORMAT),
+                createdAt: formatShortTime(new Date()),
                 isError: false,
               },
             ]
@@ -384,7 +382,7 @@ export const liveFeedbackChatSlice = createSlice({
         const newChat: ChatShape = {
           sender: ChatSender.codaveri,
           message: errorMessage,
-          createdAt: moment(new Date()).format(SHORT_TIME_FORMAT),
+          createdAt: formatShortTime(new Date()),
           isError: true,
         };
 
diff --git a/client/app/bundles/course/duplication/pages/Duplication/DestinationCourseSelector/index.jsx b/client/app/bundles/course/duplication/pages/Duplication/DestinationCourseSelector/index.jsx
index 157726cae87..a3ea5d0649b 100644
--- a/client/app/bundles/course/duplication/pages/Duplication/DestinationCourseSelector/index.jsx
+++ b/client/app/bundles/course/duplication/pages/Duplication/DestinationCourseSelector/index.jsx
@@ -8,7 +8,7 @@ import { duplicationModes } from 'course/duplication/constants';
 import { duplicateCourse } from 'course/duplication/operations';
 import { courseShape, sourceCourseShape } from 'course/duplication/propTypes';
 import { actions } from 'course/duplication/store';
-import moment, { SHORT_DATE_TIME_FORMAT } from 'lib/moment';
+import moment, { formatShortDateTime } from 'lib/moment';
 
 import NewCourseForm from './NewCourseForm';
 
@@ -85,7 +85,7 @@ class DestinationCourseSelector extends Component {
       date: tomorrow.date(),
     });
 
-    const timeNow = moment().format(SHORT_DATE_TIME_FORMAT);
+    const timeNow = formatShortDateTime(new Date());
     const newTitleValues = { title: sourceCourse.title, timestamp: timeNow };
     const initialValues = {
       destination_instance_id: currentInstanceId,
diff --git a/client/app/bundles/course/lesson-plan/pages/LessonPlanShow/LessonPlanItem/Details/Chips.jsx b/client/app/bundles/course/lesson-plan/pages/LessonPlanShow/LessonPlanItem/Details/Chips.jsx
index 399b62846cc..64f69595180 100644
--- a/client/app/bundles/course/lesson-plan/pages/LessonPlanShow/LessonPlanItem/Details/Chips.jsx
+++ b/client/app/bundles/course/lesson-plan/pages/LessonPlanShow/LessonPlanItem/Details/Chips.jsx
@@ -8,7 +8,7 @@ import { Avatar, Chip } from '@mui/material';
 import { red } from '@mui/material/colors';
 import PropTypes from 'prop-types';
 
-import moment, { SHORT_DATE_TIME_FORMAT, SHORT_TIME_FORMAT } from 'lib/moment';
+import moment, { formatShortDateTime, formatShortTime } from 'lib/moment';
 
 const translations = defineMessages({
   notPublished: {
@@ -58,17 +58,13 @@ export const formatDateRange = (startAt, endAt) => {
 
   const end = moment(endAt);
   if (!end.isValid()) {
-    return start.format(SHORT_DATE_TIME_FORMAT);
+    return formatShortDateTime(start);
   }
 
   if (end.isSame(start, 'day')) {
-    return `${start.format(SHORT_DATE_TIME_FORMAT)} - ${end.format(
-      SHORT_TIME_FORMAT,
-    )}`;
+    return `${formatShortDateTime(start)} - ${formatShortTime(end)}`;
   }
-  return `${start.format(SHORT_DATE_TIME_FORMAT)} - ${end.format(
-    SHORT_DATE_TIME_FORMAT,
-  )}`;
+  return `${formatShortDateTime(start)} - ${formatShortDateTime(end)}`;
 };
 
 class Chips extends Component {
diff --git a/client/app/bundles/course/statistics/pages/StatisticsIndex/assessments/AssessmentsStatisticsTable.tsx b/client/app/bundles/course/statistics/pages/StatisticsIndex/assessments/AssessmentsStatisticsTable.tsx
index e288b0bcb7c..07d1a144fc5 100644
--- a/client/app/bundles/course/statistics/pages/StatisticsIndex/assessments/AssessmentsStatisticsTable.tsx
+++ b/client/app/bundles/course/statistics/pages/StatisticsIndex/assessments/AssessmentsStatisticsTable.tsx
@@ -17,7 +17,7 @@ import {
 } from 'lib/helpers/url-builders';
 import { getCourseId } from 'lib/helpers/url-helpers';
 import useTranslation from 'lib/hooks/useTranslation';
-import { formatMiniDateTime } from 'lib/moment';
+import { formatMiniDateTime, formatSecondsDuration } from 'lib/moment';
 
 import AssessmentsScoreSummaryDownload from './AssessmentsScoreSummaryDownload';
 
@@ -226,14 +226,14 @@ const AssessmentsStatisticsTable: FC<Props> = (props) => {
       of: 'averageTimeTaken',
       title: t(translations.averageTimeTaken),
       sortable: true,
-      cell: (assessment) => assessment.averageTimeTaken,
+      cell: (assessment) => formatSecondsDuration(assessment.averageTimeTaken),
       csvDownloadable: true,
     },
     {
       of: 'stdevTimeTaken',
       title: t(translations.stdevTimeTaken),
       sortable: true,
-      cell: (assessment) => assessment.stdevTimeTaken,
+      cell: (assessment) => formatSecondsDuration(assessment.stdevTimeTaken),
       csvDownloadable: true,
     },
   ];
diff --git a/client/app/bundles/course/statistics/pages/StatisticsIndex/staff/StaffStatisticsTable.tsx b/client/app/bundles/course/statistics/pages/StatisticsIndex/staff/StaffStatisticsTable.tsx
index 0e63f04e89f..64ac9ea868c 100644
--- a/client/app/bundles/course/statistics/pages/StatisticsIndex/staff/StaffStatisticsTable.tsx
+++ b/client/app/bundles/course/statistics/pages/StatisticsIndex/staff/StaffStatisticsTable.tsx
@@ -7,6 +7,7 @@ import { processStaff } from 'course/statistics/utils/parseStaffResponse';
 import Table, { ColumnTemplate } from 'lib/components/table';
 import { DEFAULT_TABLE_ROWS_PER_PAGE } from 'lib/constants/sharedConstants';
 import useTranslation from 'lib/hooks/useTranslation';
+import { formatSecondsDuration } from 'lib/moment';
 
 const translations = defineMessages({
   name: {
@@ -82,14 +83,14 @@ const StaffStatisticsTable: FC<Props> = (props) => {
       title: t(translations.averageMarkingTime),
       sortable: true,
       csvDownloadable: true,
-      cell: (staff) => staff.averageMarkingTime,
+      cell: (staff) => formatSecondsDuration(staff.averageMarkingTime),
     },
     {
       of: 'stddev',
       title: t(translations.stddev),
       sortable: true,
       csvDownloadable: true,
-      cell: (staff) => staff.stddev,
+      cell: (staff) => formatSecondsDuration(staff.stddev),
     },
   ];
 
diff --git a/client/app/bundles/course/statistics/types.ts b/client/app/bundles/course/statistics/types.ts
index 253710ead8a..627587339f4 100644
--- a/client/app/bundles/course/statistics/types.ts
+++ b/client/app/bundles/course/statistics/types.ts
@@ -63,8 +63,8 @@ export interface Staff {
   name: string;
   numGraded: number;
   numStudents: number;
-  averageMarkingTime: string;
-  stddev: string;
+  averageMarkingTime: number;
+  stddev: number;
 }
 
 export interface StaffStatistics {
@@ -125,8 +125,8 @@ export interface CourseAssessment {
   maximumGrade: number;
   averageGrade: number;
   stdevGrade: number;
-  averageTimeTaken: string;
-  stdevTimeTaken: string;
+  averageTimeTaken: number;
+  stdevTimeTaken: number;
   numSubmitted: number;
   numAttempted: number;
   numLate: number;
diff --git a/client/app/lib/moment.ts b/client/app/lib/moment.ts
index d63b9cd3c3f..734189f44b2 100644
--- a/client/app/lib/moment.ts
+++ b/client/app/lib/moment.ts
@@ -1,27 +1,41 @@
 import moment from 'moment-timezone';
 
+moment.updateLocale('en', {
+  relativeTime: {
+    m: '1 minute',
+    h: '1 hour',
+    d: '1 day',
+    w: '1 week',
+    M: '1 month',
+    y: '1 year',
+  },
+});
+
 const LONG_DATE_FORMAT = 'DD MMM YYYY' as const;
 const LONG_TIME_FORMAT = 'h:mma' as const;
 const LONG_DATE_TIME_FORMAT =
   `${LONG_DATE_FORMAT}, ${LONG_TIME_FORMAT}` as const;
 
 const SHORT_DATE_FORMAT = 'DD-MM-YYYY' as const;
+const PRECISE_SECONDS_TIME_FORMAT = 'HH:mm:ss' as const;
 const PRECISE_TIME_FORMAT = 'HH:mm:ss.SS' as const;
 const PRECISE_DATE_TIME_FORMAT = `DD-MM-YY ${PRECISE_TIME_FORMAT}` as const;
 
-// TODO: Do not export these and remove all of their imports
-export const SHORT_TIME_FORMAT = 'HH:mm' as const;
-export const SHORT_DATE_TIME_FORMAT =
+const SHORT_TIME_FORMAT = 'HH:mm' as const;
+const SHORT_DATE_TIME_FORMAT =
   `${SHORT_DATE_FORMAT} ${SHORT_TIME_FORMAT}` as const;
 
 const FULL_DATE_TIME_FORMAT = 'dddd, MMMM D YYYY, HH:mm' as const;
 const MINI_DATE_TIME_FORMAT = 'D MMM YYYY HH:mm' as const;
 const MINI_DATE_TIME_YEARLESS_FORMAT = 'D MMM HH:mm' as const;
 
+const SECONDS_IN_A_DAY = 86400 as const;
+
 // TODO: Do not export moment and create the helpers here
 export default moment;
 
 type DateTimeFormatter = (input?: string | Date | null | number) => string;
+type DurationFormatter = (input?: string | null | number) => string;
 
 const formatterWith =
   (format: string): DateTimeFormatter =>
@@ -36,6 +50,7 @@ export const formatLongDate = formatterWith(LONG_DATE_FORMAT);
 export const formatLongDateTime = formatterWith(LONG_DATE_TIME_FORMAT);
 export const formatShortDateTime = formatterWith(SHORT_DATE_TIME_FORMAT);
 export const formatFullDateTime = formatterWith(FULL_DATE_TIME_FORMAT);
+export const formatShortTime = formatterWith(SHORT_TIME_FORMAT);
 export const formatPreciseTime = formatterWith(PRECISE_TIME_FORMAT);
 export const formatPreciseDateTime = formatterWith(PRECISE_DATE_TIME_FORMAT);
 
@@ -48,3 +63,23 @@ export const formatMiniDateTime: DateTimeFormatter = (input) => {
 
   return dateTime.format(MINI_DATE_TIME_FORMAT);
 };
+
+export const formatSecondsDuration: DurationFormatter = (input) => {
+  if (!input) return '--:--:--';
+  if (typeof input === 'string') {
+    input = parseInt(input, 10);
+  }
+
+  const durationDays =
+    input >= SECONDS_IN_A_DAY
+      ? // Always display days for greater precision, otherwise "40 days" gets rounded to "a month"
+        moment
+          .duration(Math.floor(input / SECONDS_IN_A_DAY), 'd')
+          .humanize(false, { d: 1_000_000_000 })
+      : '';
+
+  const durationTime = moment
+    .utc((input % SECONDS_IN_A_DAY) * 1000)
+    .format(PRECISE_SECONDS_TIME_FORMAT);
+  return [durationDays, durationTime].join('  ').trim();
+};
diff --git a/config/locales/en/time.yml b/config/locales/en/time.yml
index c88b42b72ea..58e43d52980 100644
--- a/config/locales/en/time.yml
+++ b/config/locales/en/time.yml
@@ -1,5 +1,4 @@
 en:
   time:
-    day: 'day'
     formats:
       default: '%a, %d %b %Y %I:%M:%S %p'
diff --git a/config/locales/ko/time.yml b/config/locales/ko/time.yml
index d6b2fd3d5dc..1ee43cc0eb2 100644
--- a/config/locales/ko/time.yml
+++ b/config/locales/ko/time.yml
@@ -1,5 +1,4 @@
 ko:
   time:
-    day: '일'
     formats:
       default: '%a, %Y %b %d %p %I:%M:%S'
diff --git a/config/locales/zh/time.yml b/config/locales/zh/time.yml
index 5881711a853..a3d222966aa 100644
--- a/config/locales/zh/time.yml
+++ b/config/locales/zh/time.yml
@@ -1,5 +1,4 @@
 zh:
   time:
-    day: '日期'
     formats:
       default: '%a, %Y %b %d %H:%M:%S'
diff --git a/spec/features/course/staff_statistics_spec.rb b/spec/features/course/staff_statistics_spec.rb
index c9e380f7b14..a2b1bba5374 100644
--- a/spec/features/course/staff_statistics_spec.rb
+++ b/spec/features/course/staff_statistics_spec.rb
@@ -24,7 +24,7 @@
       # Create submissions for tutors, with given submitted at and published_at
       let!(:tutor1_submissions) do
         submitted_at = 1.day.ago
-        published_at = submitted_at + 1.day + 1.hour + 1.minute + 1.second
+        published_at = submitted_at + 1.hour
         assessment = create(:assessment, :with_mcq_question, course: course)
         submission = create(:submission, :published,
                             assessment: assessment, course: course, publisher: tutor1.user,
@@ -36,7 +36,7 @@
 
       let!(:tutor2_submissions) do
         submitted_at = 2.days.ago
-        published_at = submitted_at + 2.days
+        published_at = submitted_at + 1.day + 1.hour + 1.minute + 1.second
         assessment = create(:assessment, :with_mcq_question, course: course)
         submission = create(:submission, :published,
                             assessment: assessment, course: course, publisher: tutor2.user,
@@ -48,7 +48,7 @@
 
       let!(:tutor3_submissions) do
         submitted_at = 2.days.ago
-        published_at = submitted_at + 3.days
+        published_at = submitted_at + 2.days
         assessment = create(:assessment, :with_mcq_question, course: course)
         staff_submission = create(:submission, :published,
                                   assessment: assessment, course: course, publisher: tutor3.user,
@@ -85,14 +85,14 @@
           expect(row).to have_selector('td', text: '1') # S/N
           expect(row).to have_selector('td', text: tutor1.name)
           expect(row).to have_selector('td', text: tutor1_submissions.size)
-          expect(row).to have_selector('td', text: "1 #{I18n.t('time.day')} 01:01:01")
+          expect(row).to have_selector('td', text: '01:00:00')
         end
 
         within find('tr', text: tutor2.name) do |row|
           expect(row).to have_selector('td', text: '2')
           expect(row).to have_selector('td', text: tutor2.name)
           expect(row).to have_selector('td', text: tutor2_submissions.size)
-          expect(row).to have_selector('td', text: "2 #{I18n.t('time.day')} 00:00:00")
+          expect(row).to have_selector('td', text: '1 day 01:01:01')
         end
 
         # Do not reflect staff submissions as part of staff statistics.
@@ -100,7 +100,7 @@
           expect(row).to have_selector('td', text: '3')
           expect(row).to have_selector('td', text: tutor3.name)
           expect(row).to have_selector('td', text: '1')
-          expect(row).to have_selector('td', text: "3 #{I18n.t('time.day')} 00:00:00")
+          expect(row).to have_selector('td', text: '2 days 00:00:00')
         end
 
         expect(page).not_to have_text(tutor4.name)
diff --git a/spec/helpers/application_formatters_helper_spec.rb b/spec/helpers/application_formatters_helper_spec.rb
index d86191a0cac..b9506cd46f8 100644
--- a/spec/helpers/application_formatters_helper_spec.rb
+++ b/spec/helpers/application_formatters_helper_spec.rb
@@ -314,4 +314,104 @@ def hello:
       end
     end
   end
+
+  describe '#format_rich_text_for_csv' do
+    context 'when text is nil' do
+      it 'returns empty string' do
+        expect(helper.format_rich_text_for_csv(nil)).to eq('')
+      end
+    end
+
+    context 'when text is empty' do
+      it 'returns empty string' do
+        expect(helper.format_rich_text_for_csv('')).to eq('')
+      end
+    end
+
+    context 'when text contains HTML tags' do
+      it 'strips all HTML tags' do
+        html = '<p>Hello <strong>World</strong></p>'
+        expect(helper.format_rich_text_for_csv(html)).to eq('Hello World')
+      end
+
+      it 'strips nested HTML tags' do
+        html = '<div><p><span>Test</span></p></div>'
+        expect(helper.format_rich_text_for_csv(html)).to eq('Test')
+      end
+    end
+
+    context 'when text contains HTML entities' do
+      it 'decodes &nbsp; to space' do
+        html = '<p>Hello&nbsp;World</p>'
+        expect(helper.format_rich_text_for_csv(html)).to eq('Hello World')
+      end
+
+      it 'decodes &amp; to &' do
+        html = '<p>Test&amp;Example</p>'
+        expect(helper.format_rich_text_for_csv(html)).to eq('Test&Example')
+      end
+
+      it 'decodes multiple entities' do
+        html = '<p>Hello&nbsp;World&amp;Test&lt;Example&gt;</p>'
+        expect(helper.format_rich_text_for_csv(html)).to eq('Hello World&Test<Example>')
+      end
+
+      it 'decodes numeric entities' do
+        html = '<p>&#34;Quote&#34;</p>'
+        expect(helper.format_rich_text_for_csv(html)).to eq('"Quote"')
+      end
+    end
+
+    context 'when text contains paragraph and line breaks' do
+      it 'preserves paragraph breaks as newlines' do
+        html = '<p>First paragraph</p><p>Second paragraph</p>'
+        result = helper.format_rich_text_for_csv(html)
+        expect(result).to eq("First paragraph\nSecond paragraph")
+      end
+
+      it 'preserves line breaks as newlines' do
+        html = '<p>Line 1<br />Line 2</p>'
+        result = helper.format_rich_text_for_csv(html)
+        expect(result).to eq("Line 1\nLine 2")
+      end
+
+      it 'handles complex HTML with mixed content' do
+        html = '<p>First</p><p>Second<br />Third</p><p>Fourth</p>'
+        result = helper.format_rich_text_for_csv(html)
+        expect(result).to eq("First\nSecond\nThird\nFourth")
+      end
+    end
+
+    context 'edge cases' do
+      it 'handles malformed HTML gracefully' do
+        html = '<p>Unclosed paragraph'
+        result = helper.format_rich_text_for_csv(html)
+        expect(result).to eq('Unclosed paragraph')
+      end
+
+      it 'handles text without any HTML' do
+        text = 'Plain text'
+        result = helper.format_rich_text_for_csv(text)
+        expect(result).to eq('Plain text')
+      end
+
+      it 'handles mixed plain text and HTML' do
+        html = 'Plain <strong>bold</strong> text'
+        result = helper.format_rich_text_for_csv(html)
+        expect(result).to eq('Plain bold text')
+      end
+
+      it 'handles script tags (should be stripped)' do
+        html = '<p>Safe text</p><script>alert("xss")</script>'
+        result = helper.format_rich_text_for_csv(html)
+        expect(result).to eq("Safe text\nalert(\"xss\")")
+      end
+
+      it 'handles literal & character' do
+        html = 'Peanut Butter & Jelly'
+        result = helper.format_rich_text_for_csv(html)
+        expect(result).to eq('Peanut Butter & Jelly')
+      end
+    end
+  end
 end