diff --git a/app/models/time_entry.rb b/app/models/time_entry.rb
index b784c4f2d..55d714786 100644
--- a/app/models/time_entry.rb
+++ b/app/models/time_entry.rb
@@ -191,7 +191,12 @@ class TimeEntry < ApplicationRecord
   def hours
     h = read_attribute(:hours)
     if h.is_a?(Float)
-      h.round(2)
+      # Convert the float value to a rational to avoid rounding errors
+      #
+      # Examples:
+      #  0.38333333333333336 => (23/60)   # 23 minutes
+      #  1.1166666666666667 => (67/60)    # 1 hour 7 minutes
+      (h * 60).round / 60r
     else
       h
     end
diff --git a/lib/redmine/i18n.rb b/lib/redmine/i18n.rb
index 83ecb05eb..5267c2336 100644
--- a/lib/redmine/i18n.rb
+++ b/lib/redmine/i18n.rb
@@ -50,12 +50,12 @@ module Redmine
     end
 
     def l_hours(hours)
-      hours = hours.to_f
+      hours = hours.to_r
       l((hours < 2.0 ? :label_f_hour : :label_f_hour_plural), :value => format_hours(hours))
     end
 
     def l_hours_short(hours)
-      l(:label_f_hour_short, :value => format_hours(hours.to_f))
+      l(:label_f_hour_short, :value => format_hours(hours.to_r))
     end
 
     def ll(lang, str, arg=nil)
@@ -93,8 +93,10 @@ module Redmine
       return "" if hours.blank?
 
       if Setting.timespan_format == 'minutes'
-        h = hours.floor
-        m = ((hours - h) * 60).round
+        # Ensure the hours value is rational
+        rational_hours = hours.is_a?(Rational) ? hours : (hours * 60).round / 60r
+        h = rational_hours.truncate
+        m = ((rational_hours - h) * 60).round
         "%d:%02d" % [h, m]
       else
         number_with_delimiter(sprintf('%.2f', hours.to_f), delimiter: nil)
diff --git a/test/functional/my_controller_test.rb b/test/functional/my_controller_test.rb
index b485b5c9a..252338610 100644
--- a/test/functional/my_controller_test.rb
+++ b/test/functional/my_controller_test.rb
@@ -48,14 +48,24 @@ class MyControllerTest < Redmine::ControllerTest
     preferences.save!
     with_issue =
       TimeEntry.create!(
-        :user => User.find(2), :spent_on => Date.yesterday,
+        :user => User.find(2), :spent_on => User.current.today.yesterday,
         :hours => 2.5, :activity_id => 10, :issue_id => 1
       )
     without_issue =
       TimeEntry.create!(
-        :user => User.find(2), :spent_on => Date.yesterday,
+        :user => User.find(2), :spent_on => User.current.today.yesterday,
         :hours => 3.5, :activity_id => 10, :project_id => 1
       )
+    # Issues that causes a rounding error
+    # The sum of 10m, 40m and 10m should be 1h, but it may displayed as 1h1m
+    # if hours are rounded to 2 decimals
+    #  [0.17, 0.67, 0.17].sum => 1.01
+    %w[10m 40m 10m].each do |hours|
+      TimeEntry.create!(
+        :user => User.find(2), :spent_on => User.current.today,
+        :hours => hours, :activity_id => 10, :issue_id => 1
+      )
+    end
     get :page
     assert_response :success
     assert_select "tr#time-entry-#{with_issue.id}" do
@@ -65,6 +75,10 @@ class MyControllerTest < Redmine::ControllerTest
     assert_select "tr#time-entry-#{without_issue.id}" do
       assert_select 'td.hours', :text => '3:30'
     end
+    assert_select 'tr:first' do # today's total
+      assert_select 'td.hours span.hours-int', :text => '1'
+      assert_select 'td.hours span.hours-dec', :text => ':00'
+    end
   end
 
   def test_page_with_assigned_issues_block_and_no_custom_settings
diff --git a/test/unit/time_entry_test.rb b/test/unit/time_entry_test.rb
index 8722a86cd..7bb28f675 100644
--- a/test/unit/time_entry_test.rb
+++ b/test/unit/time_entry_test.rb
@@ -87,10 +87,12 @@ class TimeEntryTest < ActiveSupport::TestCase
       "3 hours"  => 3.0,
       "12min"    => 0.2,
       "12 Min"    => 0.2,
+      "0:23"   => Rational(23, 60),  # 0.38333333333333336
+      "1:07"   => Rational(67, 60)   # 1.1166666666666667
     }
     assertions.each do |k, v|
       t = TimeEntry.new(:hours => k)
-      assert_equal v, t.hours, "Converting #{k} failed:"
+      assert v == t.hours && t.hours.is_a?(Rational), "Converting #{k} failed:"
     end
   end