diff --git a/app/models/period.rb b/app/models/period.rb
index 183c6ef8c..c3678bba4 100644
--- a/app/models/period.rb
+++ b/app/models/period.rb
@@ -69,6 +69,22 @@ class Period
       label_short: "10Y",
       label: "Last 10 Years",
       comparison_label: "vs. 10 years ago"
+    },
+    "all_time" => {
+      date_range: -> {
+        oldest_date = Current.family&.oldest_entry_date
+        # If no family or no entries exist, use a reasonable historical fallback
+        # to ensure "All Time" represents a meaningful range, not just today
+        start_date = if oldest_date && oldest_date < Date.current
+          oldest_date
+        else
+          5.years.ago.to_date
+        end
+        [ start_date, Date.current ]
+      },
+      label_short: "All",
+      label: "All Time",
+      comparison_label: "vs. beginning"
     }
   }
 
diff --git a/test/models/period_test.rb b/test/models/period_test.rb
index eaea02c59..b7e3e4f5d 100644
--- a/test/models/period_test.rb
+++ b/test/models/period_test.rb
@@ -57,4 +57,42 @@ class PeriodTest < ActiveSupport::TestCase
     expected = "#{start_date.strftime("%b %d, %Y")} to #{end_date.strftime("%b %d, %Y")}"
     assert_equal expected, period.comparison_label
   end
+
+  test "all_time period can be created" do
+    period = Period.from_key("all_time")
+    assert_equal "all_time", period.key
+    assert_equal "All Time", period.label
+    assert_equal "All", period.label_short
+    assert_equal "vs. beginning", period.comparison_label
+  end
+
+  test "all_time period uses family's oldest entry date" do
+    # Mock Current.family to return a family with oldest_entry_date
+    mock_family = mock("family")
+    mock_family.expects(:oldest_entry_date).returns(2.years.ago.to_date)
+    Current.expects(:family).at_least_once.returns(mock_family)
+
+    period = Period.from_key("all_time")
+    assert_equal 2.years.ago.to_date, period.start_date
+    assert_equal Date.current, period.end_date
+  end
+
+  test "all_time period uses fallback when no family or entries exist" do
+    Current.expects(:family).returns(nil)
+
+    period = Period.from_key("all_time")
+    assert_equal 5.years.ago.to_date, period.start_date
+    assert_equal Date.current, period.end_date
+  end
+
+  test "all_time period uses fallback when oldest_entry_date equals current date" do
+    # Mock a family that has no historical entries (oldest_entry_date returns today)
+    mock_family = mock("family")
+    mock_family.expects(:oldest_entry_date).returns(Date.current)
+    Current.expects(:family).at_least_once.returns(mock_family)
+
+    period = Period.from_key("all_time")
+    assert_equal 5.years.ago.to_date, period.start_date
+    assert_equal Date.current, period.end_date
+  end
 end