diff --git a/lib/xrechnung.rb b/lib/xrechnung.rb
index 48a6deb..c848f30 100644
--- a/lib/xrechnung.rb
+++ b/lib/xrechnung.rb
@@ -21,6 +21,7 @@
 require "xrechnung/price"
 require "xrechnung/invoice_line"
 require "xrechnung/invoice_document_reference"
+require "xrechnung/invoice_period"
 require "builder"
 
 module Xrechnung
@@ -168,6 +169,10 @@ class Document
     #   @return [Xrechnung::InvoiceDocumentReference]
     member :billing_reference, type: Xrechnung::InvoiceDocumentReference, optional: true
 
+    # @!attribute invoice_period
+    #   @return [Xrechnung::InvoicePeriod]
+    member :invoice_period, type: Xrechnung::InvoicePeriod, optional: true
+
     # Contract reference BT-12
     #
     # Eine eindeutige Bezeichnung des Vertrages (z. B. Vertragsnummer).
@@ -260,11 +265,15 @@ def to_xml(indent: 2, target: "")
           xml.cbc :Note, note
         end
 
-        xml.cbc :TaxPointDate, tax_point_date
+        xml.cbc :TaxPointDate, tax_point_date unless tax_point_date.nil?
         xml.cbc :DocumentCurrencyCode, document_currency_code
         xml.cbc :TaxCurrencyCode, tax_currency_code
         xml.cbc :BuyerReference, buyer_reference
 
+        unless members[:invoice_period][:optional] && invoice_period.nil?
+          invoice_period&.to_xml(xml)
+        end
+
         xml.cac :OrderReference do
           xml.cbc :ID, purchase_order_reference
           unless members[:sales_order_reference][:optional] && sales_order_reference.nil?
diff --git a/lib/xrechnung/invoice_period.rb b/lib/xrechnung/invoice_period.rb
new file mode 100644
index 0000000..55f8f8f
--- /dev/null
+++ b/lib/xrechnung/invoice_period.rb
@@ -0,0 +1,20 @@
+module Xrechnung
+  class InvoicePeriod
+    include MemberContainer
+
+    # @!attribute start_date
+    #   @return [Date]
+    member :start_date, type: Date
+
+    # @!attribute end_date
+    #   @return [Date]
+    member :end_date, type: Date
+
+    def to_xml(xml)
+      xml.cac :InvoicePeriod do
+        xml.cbc :StartDate, start_date
+        xml.cbc :EndDate, end_date
+      end
+    end
+  end
+end
diff --git a/spec/fixtures/xrechnung.xml b/spec/fixtures/xrechnung.xml
index 436c047..658fb27 100644
--- a/spec/fixtures/xrechnung.xml
+++ b/spec/fixtures/xrechnung.xml
@@ -12,6 +12,10 @@
   <cbc:DocumentCurrencyCode>EUR</cbc:DocumentCurrencyCode>
   <cbc:TaxCurrencyCode>EUR</cbc:TaxCurrencyCode>
   <cbc:BuyerReference>9900 0000 - 1234 56 - 23</cbc:BuyerReference>
+  <cac:InvoicePeriod>
+    <cbc:StartDate>2021-04-01</cbc:StartDate>
+    <cbc:EndDate>2021-04-30</cbc:EndDate>
+  </cac:InvoicePeriod>
   <cac:OrderReference>
     <cbc:ID>0815-99-1</cbc:ID>
   </cac:OrderReference>
diff --git a/spec/xrechnung_spec.rb b/spec/xrechnung_spec.rb
index 2acb167..9f547f3 100644
--- a/spec/xrechnung_spec.rb
+++ b/spec/xrechnung_spec.rb
@@ -29,6 +29,10 @@
     doc.billing_reference.id         = "Vorangegangene Rechnung 23423"
     doc.billing_reference.issue_date = Date.new(2020, 4, 23)
 
+    doc.invoice_period            = Xrechnung::InvoicePeriod.new
+    doc.invoice_period.start_date = Date.new(2021, 4, 1)
+    doc.invoice_period.end_date   = Date.new(2021, 4, 30)
+
     doc.contract_document_reference_id = "23871349"
     doc.project_reference_id           = "Bauvorhaben Glücksstraße 4"