diff --git a/README.md b/README.md
index 7f3dbd1..534577e 100644
--- a/README.md
+++ b/README.md
@@ -90,6 +90,33 @@ MovementDetail.filterable(
 Unparseable values are dropped silently (the filter is a no-op), so a bad query
 param can never raise.
 
+#### Datetime columns: a bare day names the whole day
+
+On a column holding an **instant** (`t.datetime`), a bound given as a bare day
+(`2026-03-01`) names that day **whole**, both edges included. Read as an instant
+it would mean the day's midnight, and would drop every row recorded during the
+day it names:
+
+```ruby
+# quoted_at is a datetime column; rows at 09:00 and at 17:30 on 2026-03-01
+MovementDetail.filterable(filters: { quoted_at: { since: '2026-03-01' } })
+# => both rows, not just a midnight one
+
+MovementDetail.filterable(filters: { quoted_at: { after: '2026-03-01' } })
+# => neither: the day is excluded whole, the first instant kept is the next midnight
+```
+
+A bound carrying an **hour** asks about an instant and is honoured to the second:
+
+```ruby
+MovementDetail.filterable(filters: { quoted_at: { since: '2026-03-01T12:00:00Z' } })
+# => the 09:00 row only
+```
+
+Which day an instant belongs to is decided in `Time.zone` when the application
+sets one, and in the system zone otherwise, so the same bound answers the same
+way whatever zone the server runs in. On a `t.date` column nothing changes.
+
 ### Equality filters (`Equatable`)
 
 Each declared equatable attribute reads `filters[<attribute>]` directly: a
diff --git a/lib/filterable/datable.rb b/lib/filterable/datable.rb
index 62dab3e..922dd2a 100644
--- a/lib/filterable/datable.rb
+++ b/lib/filterable/datable.rb
@@ -5,25 +5,53 @@ module Filterable
   module Datable
     module_function
 
-    # Coerce a raw filter value into a Date/Time, or nil when it cannot be parsed,
-    # so a malformed query param narrows nothing instead of raising.
+    # Coerce a raw filter value into the bound it names: a Date when it names a
+    # whole day, a Time when it names an instant, or nil when it cannot be
+    # parsed, so a malformed query param narrows nothing instead of raising.
     #
     # @api private
     # @param value [Date, Time, String] the raw bound from the params.
-    # @return [Date, Time, nil] the parsed value, or nil when unparseable.
+    # @return [Date, Time, nil] the parsed bound, or nil when unparseable.
     def parse(value)
       case value
-      when Date, Time
-        value
-      else
-        begin
-          Time.parse(value.to_s)
-        rescue ArgumentError
-          nil
-        end
+      when DateTime then value.to_time
+      when Time, Date then value
+      else parse_bound(value.to_s)
       end
     end
 
+    def parse_bound(string)
+      parts = Date._parse(string)
+      day = Date.new(parts[:year], parts[:mon], parts[:mday])
+      parts.key?(:hour) ? (Time.zone || Time).parse(string) : day
+    rescue TypeError, ArgumentError
+      nil
+    end
+
+    def whole_day?(bound)
+      bound.instance_of?(Date)
+    end
+
+    def midnight(day)
+      Time.zone ? day.in_time_zone : day.to_time
+    end
+
+    def on_or_before(field, bound)
+      whole_day?(bound) ? field.lt(midnight(bound + 1)) : field.lteq(bound)
+    end
+
+    def strictly_before(field, bound)
+      field.lt(whole_day?(bound) ? midnight(bound) : bound)
+    end
+
+    def on_or_after(field, bound)
+      field.gteq(whole_day?(bound) ? midnight(bound) : bound)
+    end
+
+    def strictly_after(field, bound)
+      whole_day?(bound) ? field.gteq(midnight(bound + 1)) : field.gt(bound)
+    end
+
     # Whitelist the params to the declared datable attributes, keeping their
     # public names. An attribute whose value is not a hash of bounds (e.g.
     # +filters[date]=2026-01-01+ from a query string) is dropped, so a malformed
diff --git a/lib/filterable/datable/after.rb b/lib/filterable/datable/after.rb
index 40f8a25..c3903e4 100644
--- a/lib/filterable/datable/after.rb
+++ b/lib/filterable/datable/after.rb
@@ -16,7 +16,7 @@ module After
       def call(params, scope)
         entries = Filterable::Datable.accepted(params, scope, :after)
         entries.reduce(scope) do |sub_scope, (_name, target, _bounds, parsed)|
-          Filterable::Target.narrow(sub_scope, target) { |field| field.gt(parsed[:after]) }
+          Filterable::Target.narrow(sub_scope, target) { |field| Filterable::Datable.strictly_after(field, parsed[:after]) }
         end
       end
 
diff --git a/lib/filterable/datable/before.rb b/lib/filterable/datable/before.rb
index 89b1c20..9e978f7 100644
--- a/lib/filterable/datable/before.rb
+++ b/lib/filterable/datable/before.rb
@@ -16,7 +16,7 @@ module Before
       def call(params, scope)
         entries = Filterable::Datable.accepted(params, scope, :before)
         entries.reduce(scope) do |sub_scope, (_name, target, _bounds, parsed)|
-          Filterable::Target.narrow(sub_scope, target) { |field| field.lt(parsed[:before]) }
+          Filterable::Target.narrow(sub_scope, target) { |field| Filterable::Datable.strictly_before(field, parsed[:before]) }
         end
       end
 
diff --git a/lib/filterable/datable/range.rb b/lib/filterable/datable/range.rb
index b8a3fe9..754edcf 100644
--- a/lib/filterable/datable/range.rb
+++ b/lib/filterable/datable/range.rb
@@ -18,7 +18,8 @@ def call(params, scope)
         entries = Filterable::Datable.accepted(params, scope, :from, :to)
         entries.reduce(scope) do |sub_scope, (_name, target, _bounds, parsed)|
           Filterable::Target.narrow(sub_scope, target) do |field|
-            field.gteq(parsed[:from]).and(field.lteq(parsed[:to]))
+            Filterable::Datable.on_or_after(field, parsed[:from])
+                               .and(Filterable::Datable.on_or_before(field, parsed[:to]))
           end
         end
       end
diff --git a/lib/filterable/datable/since.rb b/lib/filterable/datable/since.rb
index ded420e..abff9a3 100644
--- a/lib/filterable/datable/since.rb
+++ b/lib/filterable/datable/since.rb
@@ -16,7 +16,7 @@ module Since
       def call(params, scope)
         entries = Filterable::Datable.accepted(params, scope, :since)
         entries.reduce(scope) do |sub_scope, (_name, target, _bounds, parsed)|
-          Filterable::Target.narrow(sub_scope, target) { |field| field.lteq(parsed[:since]) }
+          Filterable::Target.narrow(sub_scope, target) { |field| Filterable::Datable.on_or_before(field, parsed[:since]) }
         end
       end
 
diff --git a/spec/datable_datetime_spec.rb b/spec/datable_datetime_spec.rb
new file mode 100644
index 0000000..07d0c06
--- /dev/null
+++ b/spec/datable_datetime_spec.rb
@@ -0,0 +1,87 @@
+# frozen_string_literal: true
+
+require 'spec_helper'
+
+RSpec.describe Filterable::Concerns::Datable, 'on a datetime column' do
+  let!(:morning) { MovementDetail.create!(quoted_at: Time.utc(2026, 3, 1, 9, 0)) }
+  let!(:evening) { MovementDetail.create!(quoted_at: Time.utc(2026, 3, 1, 17, 30)) }
+  let!(:next_day) { MovementDetail.create!(quoted_at: Time.utc(2026, 3, 2, 9, 0)) }
+
+  def filter(bounds)
+    MovementDetail.where.not(quoted_at: nil).filterable(filters: { quoted_at: bounds })
+  end
+
+  describe 'a bound given as a bare day names the whole day' do
+    it 'keeps every record of the day under a since ceiling' do
+      expect(filter(since: '2026-03-01')).to contain_exactly(morning, evening)
+    end
+
+    it 'keeps every record of the day under a from/to range' do
+      expect(filter(from: '2026-03-01', to: '2026-03-01')).to contain_exactly(morning, evening)
+    end
+
+    it 'excludes the whole day under a before floor' do
+      expect(filter(before: '2026-03-02')).to contain_exactly(morning, evening)
+    end
+
+    it 'keeps nothing of the day it floors out' do
+      expect(filter(before: '2026-03-01')).to be_empty
+    end
+
+    it 'excludes the whole day under an after floor' do
+      expect(filter(after: '2026-03-01')).to contain_exactly(next_day)
+    end
+  end
+
+  describe 'a bound carrying an hour is honoured to the second' do
+    it 'cuts inside the day on since' do
+      expect(filter(since: '2026-03-01T12:00:00Z')).to contain_exactly(morning)
+    end
+
+    it 'cuts inside the day on after' do
+      expect(filter(after: '2026-03-01T12:00:00Z')).to contain_exactly(evening, next_day)
+    end
+
+    it 'cuts inside the day on before' do
+      expect(filter(before: '2026-03-01T12:00:00Z')).to contain_exactly(morning)
+    end
+
+    it 'cuts inside the day on a range' do
+      expect(filter(from: '2026-03-01T12:00:00Z', to: '2026-03-02T12:00:00Z'))
+        .to contain_exactly(evening, next_day)
+    end
+  end
+
+  describe 'the day is cut in the application zone' do
+    let!(:paris_next_day) { MovementDetail.create!(quoted_at: Time.utc(2026, 3, 1, 23, 30)) }
+
+    around do |example|
+      Time.use_zone('Europe/Paris') { example.run }
+    end
+
+    it 'leaves out an instant that already belongs to the next day there' do
+      expect(filter(since: '2026-03-01')).to contain_exactly(morning, evening)
+    end
+
+    it 'keeps it under the day it belongs to there' do
+      expect(filter(from: '2026-03-02', to: '2026-03-02')).to contain_exactly(next_day, paris_next_day)
+    end
+  end
+
+  describe 'a date column is left as it was' do
+    let!(:january) { MovementDetail.create!(value_date: Date.new(2026, 1, 1)) }
+    let!(:february) { MovementDetail.create!(value_date: Date.new(2026, 2, 1)) }
+
+    it 'keeps the bound inclusive on since' do
+      result = MovementDetail.where.not(value_date: nil).filterable(filters: { value_date: { since: '2026-02-01' } })
+
+      expect(result).to contain_exactly(january, february)
+    end
+
+    it 'keeps the bound exclusive on after' do
+      result = MovementDetail.where.not(value_date: nil).filterable(filters: { value_date: { after: '2026-01-01' } })
+
+      expect(result).to contain_exactly(february)
+    end
+  end
+end
diff --git a/spec/spec_helper.rb b/spec/spec_helper.rb
index c1e712f..fa1b524 100644
--- a/spec/spec_helper.rb
+++ b/spec/spec_helper.rb
@@ -63,7 +63,7 @@ class MovementDetail < ActiveRecord::Base
   scope :cheaper_than,  ->(cents) { where(gross_amount_cents: ...cents) }
   scope :costlier_than, ->(cents) { where(gross_amount_cents: cents..) }
 
-  datable :value_date, :booking_date, account_opened: { account: :opened_on }
+  datable :value_date, :booking_date, :quoted_at, account_opened: { account: :opened_on }
   sortable :value_date, :gross_amount_cents
   equatable :reference, :gross_amount_cents,
             account_name: { account: :name }, bank_name: { account: { bank: :name } },
diff --git a/spec/support/schema.rb b/spec/support/schema.rb
index ed41504..6d77b4a 100644
--- a/spec/support/schema.rb
+++ b/spec/support/schema.rb
@@ -26,6 +26,7 @@ def define
       create_table :movement_details, force: true do |t|
         t.date :value_date
         t.date :booking_date
+        t.datetime :quoted_at
         t.integer :gross_amount_cents
         t.string :reference
         t.integer :account_id