diff --git a/app/models/user.rb b/app/models/user.rb
index 5421b56ce..d13c27b2f 100644
--- a/app/models/user.rb
+++ b/app/models/user.rb
@@ -120,7 +120,10 @@ class User < ApplicationRecord
     where("username ILIKE ? OR email ILIKE ? OR document_number ILIKE ?", search, search, search)
   end
   scope :between_ages, ->(from, to, at_time: Time.current) do
-    where(date_of_birth: (at_time - to.years).beginning_of_year..(at_time - from.years).end_of_year)
+    start_date = at_time - (to + 1).years + 1.day
+    end_date = at_time - from.years
+
+    where(date_of_birth: start_date.beginning_of_day..end_date.end_of_day)
   end
 
   before_validation :clean_document_number
diff --git a/spec/models/budget/stats_spec.rb b/spec/models/budget/stats_spec.rb
index d076d9c0b..54a133428 100644
--- a/spec/models/budget/stats_spec.rb
+++ b/spec/models/budget/stats_spec.rb
@@ -159,7 +159,7 @@ describe Budget::Stats do
   describe "#participants_by_age" do
     it "returns the age groups hash" do
       [21, 22, 23, 23, 34, 42, 43, 44, 50, 51].each do |age|
-        create(:user, date_of_birth: budget.phases.balloting.ends_at - age.years)
+        create(:user, date_of_birth: budget.phases.balloting.ends_at - age.years - rand(0..11).months)
       end
 
       allow(stats).to receive(:participants).and_return(User.all)
@@ -182,7 +182,7 @@ describe Budget::Stats do
       budget = travel_to(50.years.ago) { create(:budget, :finished) }
 
       [21, 22, 23, 23, 34, 42, 43, 44, 50, 51].each do |age|
-        create(:user, date_of_birth: budget.phases.balloting.ends_at - age.years)
+        create(:user, date_of_birth: budget.phases.balloting.ends_at - age.years - rand(0..11).months)
       end
 
       stats = Budget::Stats.new(budget)
diff --git a/spec/models/poll/stats_spec.rb b/spec/models/poll/stats_spec.rb
index 9bf5f56c2..7b962a2c0 100644
--- a/spec/models/poll/stats_spec.rb
+++ b/spec/models/poll/stats_spec.rb
@@ -169,7 +169,7 @@ describe Poll::Stats do
     it "returns stats based on what happened when the voting took place" do
       travel_to(100.years.ago) do
         [16, 18, 32, 32, 33, 34, 64, 65, 71, 73, 90, 99, 105].each do |age|
-          create(:user, date_of_birth: age.years.ago)
+          create(:user, date_of_birth: age.years.ago - rand(0..11).months)
         end
 
         create(:poll, starts_at: 1.minute.from_now, ends_at: 2.minutes.from_now)
diff --git a/spec/models/user_spec.rb b/spec/models/user_spec.rb
index f3e59ffd6..62a0663be 100644
--- a/spec/models/user_spec.rb
+++ b/spec/models/user_spec.rb
@@ -438,6 +438,80 @@ describe User do
         expect(User.between_ages(51, 100).count).to eq 1
       end
 
+      it "does not consider that people born in the same year share the same age" do
+        april_1st_user = create(:user, date_of_birth: Time.zone.local(2001, 4, 1))
+        april_2nd_user = create(:user, date_of_birth: Time.zone.local(2001, 4, 2))
+        april_3rd_user = create(:user, date_of_birth: Time.zone.local(2001, 4, 3))
+
+        travel_to "2021-04-02" do
+          expect(User.between_ages(18, 19)).to eq [april_3rd_user]
+          expect(User.between_ages(20, 21)).to match_array [april_1st_user, april_2nd_user]
+          expect(User.between_ages(19, 20)).to match_array [april_1st_user, april_2nd_user, april_3rd_user]
+        end
+      end
+
+      it "works on leap years with users born on leap years" do
+        leap_day_user = create(:user, date_of_birth: Time.zone.local(2000, 2, 29))
+        march_1st_user = create(:user, date_of_birth: Time.zone.local(2000, 3, 1))
+
+        travel_to "2024-02-28" do
+          expect(User.between_ages(22, 23)).to match_array [leap_day_user, march_1st_user]
+          expect(User.between_ages(23, 24)).to match_array [leap_day_user, march_1st_user]
+          expect(User.between_ages(24, 25)).to eq []
+        end
+
+        travel_to "2024-02-29" do
+          expect(User.between_ages(22, 23)).to eq [march_1st_user]
+          expect(User.between_ages(23, 24)).to eq [leap_day_user, march_1st_user]
+          expect(User.between_ages(24, 25)).to eq [leap_day_user]
+        end
+
+        travel_to "2024-03-01" do
+          expect(User.between_ages(22, 23)).to eq []
+          expect(User.between_ages(23, 24)).to match_array [leap_day_user, march_1st_user]
+          expect(User.between_ages(24, 25)).to match_array [leap_day_user, march_1st_user]
+        end
+      end
+
+      it "works on non-leap years with users born on leap years" do
+        leap_day_user = create(:user, date_of_birth: Time.zone.local(2000, 2, 29))
+        march_1st_user = create(:user, date_of_birth: Time.zone.local(2000, 3, 1))
+
+        travel_to "2023-02-28" do
+          expect(User.between_ages(21, 22)).to match_array [leap_day_user, march_1st_user]
+          expect(User.between_ages(22, 23)).to match_array [leap_day_user, march_1st_user]
+          expect(User.between_ages(23, 24)).to eq []
+        end
+
+        travel_to "2023-03-01" do
+          expect(User.between_ages(21, 22)).to eq []
+          expect(User.between_ages(22, 23)).to match_array [leap_day_user, march_1st_user]
+          expect(User.between_ages(23, 24)).to match_array [leap_day_user, march_1st_user]
+        end
+      end
+
+      it "works on leap years with users born on non-leap years" do
+        march_1st_user = create(:user, date_of_birth: Time.zone.local(2001, 3, 1))
+
+        travel_to "2024-02-28" do
+          expect(User.between_ages(21, 22)).to eq [march_1st_user]
+          expect(User.between_ages(22, 23)).to eq [march_1st_user]
+          expect(User.between_ages(23, 24)).to eq []
+        end
+
+        travel_to "2024-02-29" do
+          expect(User.between_ages(21, 22)).to eq [march_1st_user]
+          expect(User.between_ages(22, 23)).to eq [march_1st_user]
+          expect(User.between_ages(23, 24)).to eq []
+        end
+
+        travel_to "2024-03-01" do
+          expect(User.between_ages(21, 22)).to eq []
+          expect(User.between_ages(22, 23)).to match_array [march_1st_user]
+          expect(User.between_ages(23, 24)).to match_array [march_1st_user]
+        end
+      end
+
       it "returns users between certain ages on a reference date" do
         reference_date = 20.years.ago