diff --git a/History.md b/History.md
index b2b4ab64..e8f81cdd 100644
--- a/History.md
+++ b/History.md
@@ -1,4 +1,6 @@
 #558
+#686
+#739
 
 2.16.2
 =======
diff --git a/library/src/main/java/org/mustangproject/XMLTools.java b/library/src/main/java/org/mustangproject/XMLTools.java
index d890c3d1..3fd71c63 100644
--- a/library/src/main/java/org/mustangproject/XMLTools.java
+++ b/library/src/main/java/org/mustangproject/XMLTools.java
@@ -129,7 +129,13 @@ public class XMLTools extends XMLWriter {
 	 * @return a util.Date, or null, if not parseable
 	 */
 	public static Date tryDate(String toParse) {
-		final SimpleDateFormat formatter = ZUGFeRDDateFormat.DATE.getFormatter();
+		SimpleDateFormat formatter = null;
+		if (toParse.contains("-")) {
+			// from ubl
+			 formatter = new SimpleDateFormat("yyyy-MM-dd");
+		} else {
+			formatter = ZUGFeRDDateFormat.DATE.getFormatter();
+		}
 		try {
 			return formatter.parse(toParse);
 		} catch (final Exception e) {
diff --git a/library/src/main/java/org/mustangproject/ZUGFeRD/ZUGFeRDInvoiceImporter.java b/library/src/main/java/org/mustangproject/ZUGFeRD/ZUGFeRDInvoiceImporter.java
index 6e5eb051..dc261749 100644
--- a/library/src/main/java/org/mustangproject/ZUGFeRD/ZUGFeRDInvoiceImporter.java
+++ b/library/src/main/java/org/mustangproject/ZUGFeRD/ZUGFeRDInvoiceImporter.java
@@ -775,6 +775,21 @@ public class ZUGFeRDInvoiceImporter {
 			}
 		}
 
+		xpr = xpath.compile("/*[local-name()=\"Invoice\"]/*[local-name()=\"InvoicePeriod\"]/*"); //UBL only
+		NodeList periodNodes = (NodeList) xpr.evaluate(getDocument(), XPathConstants.NODESET);
+
+		for (int periodChildIndex = 0; periodChildIndex < periodNodes.getLength(); periodChildIndex++) {
+			String localName=periodNodes.item(periodChildIndex).getLocalName();
+			if ((localName != null) && (periodNodes.item(periodChildIndex).getLocalName().equals("StartDate"))) {
+				deliveryPeriodStart = XMLTools.trimOrNull(periodNodes.item(periodChildIndex));
+			}
+			if ((localName != null) && (periodNodes.item(periodChildIndex).getLocalName().equals("EndDate"))) {
+				deliveryPeriodEnd = XMLTools.trimOrNull(periodNodes.item(periodChildIndex));
+			}
+
+		}
+
+
 		if ((deliveryPeriodStart != null) && (deliveryPeriodEnd != null)) {
 			zpp.setDetailedDeliveryPeriod(XMLTools.tryDate(deliveryPeriodStart), XMLTools.tryDate(deliveryPeriodEnd));
 		} else if (deliveryPeriodStart != null) {
diff --git a/library/src/test/java/org/mustangproject/ZUGFeRD/ZF2PushTest.java b/library/src/test/java/org/mustangproject/ZUGFeRD/ZF2PushTest.java
index b1b61257..10f28a3a 100644
--- a/library/src/test/java/org/mustangproject/ZUGFeRD/ZF2PushTest.java
+++ b/library/src/test/java/org/mustangproject/ZUGFeRD/ZF2PushTest.java
@@ -32,6 +32,7 @@ import java.text.SimpleDateFormat;
 import java.util.Date;
 import java.util.List;
 
+import com.fasterxml.jackson.databind.ObjectMapper;
 import org.mustangproject.*;
 import org.junit.FixMethodOrder;
 import org.junit.runners.MethodSorters;
@@ -254,7 +255,7 @@ public class ZF2PushTest extends TestCase {
 			//	ze.setTransaction(new Invoice().setDueDate(new Date()).setIssueDate(new Date()).setDeliveryDate(new Date()).setSender(new TradeParty(orgname,"teststr", "55232","teststadt","DE")).setOwnTaxID("4711").setOwnVATID("DE0815").setRecipient(new TradeParty("Franz Müller", "teststr.12", "55232", "Entenhausen", "DE")).setNumber(number)
 			//					.addItem(new Item(new Product("Testprodukt", "", "C62", new BigDecimal(19)), amount, new BigDecimal(1.0)).addAllowance(new Allowance().setPercent(new BigDecimal(50)))));
 
-			ze.setTransaction(new Invoice().setDueDate(new Date()).setIssueDate(new Date())
+			Invoice i=new Invoice().setDueDate(new Date()).setIssueDate(new Date())
 				.setSender(new TradeParty(orgname, "teststr", "55232", "teststadt", "DE").addTaxID("4711").addVATID("DE0815"))
 				.setRecipient(new TradeParty("Franz Müller", "teststr.12", "55232", "Entenhausen", "DE")
 					.setContact(new Contact("contact testname", "123456", "contact.testemail@example.org").setFax("0911623562")))
@@ -263,8 +264,9 @@ public class ZF2PushTest extends TestCase {
 				.addItem(new Item(new Product("Testprodukt", "", "C62", new BigDecimal(19)), amount, new BigDecimal(1.0)).addAllowance(new Allowance(new BigDecimal("0.1"))))
 				.addItem(new Item(new Product("Testprodukt", "", "C62", new BigDecimal(19)), amount, new BigDecimal(1.0)).addAllowance(new Allowance().setPercent(new BigDecimal(50))))
 				.addItem(new Item(new Product("Testprodukt", "", "C62", new BigDecimal(19)), amount, new BigDecimal(2.0)).addCharge(new Charge(new BigDecimal(1)).setReasonCode("ABK").setReason("AnotherReason")))
-				.addItem(new Item(new Product("Testprodukt", "", "C62", new BigDecimal(19)), amount, new BigDecimal(1.0)).addCharge(new Charge(new BigDecimal(1))).addAllowance(new Allowance(new BigDecimal("1"))))
-			);
+				.addItem(new Item(new Product("Testprodukt", "", "C62", new BigDecimal(19)), amount, new BigDecimal(1.0)).addCharge(new Charge(new BigDecimal(1))).addAllowance(new Allowance(new BigDecimal("1"))));
+			ze.setTransaction(i);
+
 
 			String theXML = new String(ze.getProvider().getXML());
 			assertTrue(theXML.contains("<rsm:CrossIndustryInvoice"));
@@ -593,6 +595,9 @@ public class ZF2PushTest extends TestCase {
 			assertEquals(1, i.getInvoiceReferencedDocuments().size());
 			assertEquals("abcd1234", i.getInvoiceReferencedDocuments().get(0).getIssuerAssignedID());
 			assertEquals("4304171000002", i.getRecipient().getGlobalID());
+			SimpleDateFormat sdf=new SimpleDateFormat("yyyyMMdd");
+			assertEquals(occurrenceFrom, sdf.format(i.getDetailedDeliveryPeriodFrom()));
+			assertEquals(occurrenceTo, sdf.format(i.getDetailedDeliveryPeriodTo()));
 			assertEquals("2001015001325", i.getZFItems()[0].getProduct().getGlobalID());
 			assertEquals(orgID, i.getSender().getID());
 			assertEquals("Verwendungszweck", i.getPaymentReference());
diff --git a/library/src/test/java/org/mustangproject/ZUGFeRD/ZF2ZInvoiceImporterTest.java b/library/src/test/java/org/mustangproject/ZUGFeRD/ZF2ZInvoiceImporterTest.java
index 6cef6ab2..76fec675 100644
--- a/library/src/test/java/org/mustangproject/ZUGFeRD/ZF2ZInvoiceImporterTest.java
+++ b/library/src/test/java/org/mustangproject/ZUGFeRD/ZF2ZInvoiceImporterTest.java
@@ -441,6 +441,34 @@ public class ZF2ZInvoiceImporterTest extends ResourceCase {
 		}
 
 
+	}
+
+	public void testImportUBLPeriods() { // Confirm some basics also work with UBL credit notes
+		File ublinputFile = getResourceAsFile("ubl/periods.ubl.xml");
+		try {
+			ZUGFeRDInvoiceImporter zii = new ZUGFeRDInvoiceImporter();
+			zii.doIgnoreCalculationErrors();
+			zii.setInputStream(new FileInputStream(ublinputFile));
+
+
+			CalculatedInvoice i = new CalculatedInvoice();
+			zii.extractInto(i);
+			assertEquals("123", i.getNumber());
+			assertEquals("1.48", i.getGrandTotal().toString());
+			SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd");
+
+			assertEquals("2020-10-01", sdf.format(i.getDetailedDeliveryPeriodFrom()));
+			assertEquals("2020-10-05", sdf.format(i.getDetailedDeliveryPeriodTo()));
+
+		} catch (IOException e) {
+			fail("IOException not expected");
+		} catch (XPathExpressionException e) {
+			throw new RuntimeException(e);
+		} catch (ParseException e) {
+			throw new RuntimeException(e);
+		}
+
+
 	}
 
 
diff --git a/library/src/test/resources/ubl/periods.ubl.xml b/library/src/test/resources/ubl/periods.ubl.xml
new file mode 100644
index 00000000..d9387bfd
--- /dev/null
+++ b/library/src/test/resources/ubl/periods.ubl.xml
@@ -0,0 +1,197 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<Invoice xmlns="urn:oasis:names:specification:ubl:schema:xsd:Invoice-2" xmlns:cac="urn:oasis:names:specification:ubl:schema:xsd:CommonAggregateComponents-2" xmlns:cbc="urn:oasis:names:specification:ubl:schema:xsd:CommonBasicComponents-2" xmlns:ccts="urn:un:unece:uncefact:documentation:2" xmlns:qdt="urn:oasis:names:specification:ubl:schema:xsd:QualifiedDataTypes-2" xmlns:udt="urn:oasis:names:specification:ubl:schema:xsd:UnqualifiedDataTypes-2">
+  <cbc:CustomizationID>urn:cen.eu:en16931:2017#conformant#urn:factur-x.eu:1p0:extended</cbc:CustomizationID>
+  <cbc:ID>123</cbc:ID>
+  <cbc:IssueDate>2025-02-10</cbc:IssueDate>
+  <cbc:DueDate>2025-02-10</cbc:DueDate>
+  <cbc:InvoiceTypeCode>380</cbc:InvoiceTypeCode>
+  <cbc:Note>document level 1/2</cbc:Note>
+  <cbc:Note>document level 2/2</cbc:Note>
+  <cbc:DocumentCurrencyCode>CHF</cbc:DocumentCurrencyCode>
+  <cac:InvoicePeriod>
+    <cbc:StartDate>2020-10-01</cbc:StartDate>
+    <cbc:EndDate>2020-10-05</cbc:EndDate>
+    <cbc:DescriptionCode>432</cbc:DescriptionCode>
+  </cac:InvoicePeriod>
+  <cac:OrderReference>
+    <cbc:ID>28934</cbc:ID>
+    <cbc:SalesOrderID>9384</cbc:SalesOrderID>
+  </cac:OrderReference>
+  <cac:BillingReference>
+    <cac:InvoiceDocumentReference>
+      <cbc:ID>abc123</cbc:ID>
+    </cac:InvoiceDocumentReference>
+  </cac:BillingReference>
+  <cac:ContractDocumentReference>
+    <cbc:ID>376zreurzu0983</cbc:ID>
+  </cac:ContractDocumentReference>
+  <cac:AccountingSupplierParty>
+    <cac:Party>
+      <cbc:EndpointID schemeID="EM">sender@test.org</cbc:EndpointID>
+      <cac:PartyIdentification>
+        <cbc:ID>0009845</cbc:ID>
+      </cac:PartyIdentification>
+      <cac:PostalAddress>
+        <cbc:StreetName>teststr</cbc:StreetName>
+        <cbc:CityName>teststadt</cbc:CityName>
+        <cbc:PostalZone>55232</cbc:PostalZone>
+        <cac:Country>
+          <cbc:IdentificationCode>DE</cbc:IdentificationCode>
+        </cac:Country>
+      </cac:PostalAddress>
+      <cac:PartyTaxScheme>
+        <cbc:CompanyID>DE0815</cbc:CompanyID>
+        <cac:TaxScheme>
+          <cbc:ID>VAT</cbc:ID>
+        </cac:TaxScheme>
+      </cac:PartyTaxScheme>
+      <cac:PartyTaxScheme>
+        <cbc:CompanyID>9990815</cbc:CompanyID>
+        <cac:TaxScheme>
+          <cbc:ID>NOVAT</cbc:ID>
+        </cac:TaxScheme>
+      </cac:PartyTaxScheme>
+      <cac:PartyLegalEntity>
+        <cbc:RegistrationName>Test company</cbc:RegistrationName>
+      </cac:PartyLegalEntity>
+    </cac:Party>
+  </cac:AccountingSupplierParty>
+  <cac:AccountingCustomerParty>
+    <cac:Party>
+      <cbc:EndpointID schemeID="EM">recipient@test.org</cbc:EndpointID>
+      <cac:PartyIdentification>
+        <cbc:ID>0088:4304171000002</cbc:ID>
+      </cac:PartyIdentification>
+      <cac:PostalAddress>
+        <cbc:StreetName>teststr.12</cbc:StreetName>
+        <cbc:AdditionalStreetName>Hinterhaus 3</cbc:AdditionalStreetName>
+        <cbc:CityName>Entenhausen</cbc:CityName>
+        <cbc:PostalZone>55232</cbc:PostalZone>
+        <cac:Country>
+          <cbc:IdentificationCode>DE</cbc:IdentificationCode>
+        </cac:Country>
+      </cac:PostalAddress>
+      <cac:PartyTaxScheme>
+        <cbc:CompanyID>DE4711</cbc:CompanyID>
+        <cac:TaxScheme>
+          <cbc:ID>VAT</cbc:ID>
+        </cac:TaxScheme>
+      </cac:PartyTaxScheme>
+      <cac:PartyLegalEntity>
+        <cbc:RegistrationName>Franz Müller</cbc:RegistrationName>
+      </cac:PartyLegalEntity>
+      <cac:Contact>
+        <cbc:Telephone>01779999999</cbc:Telephone>
+        <cbc:ElectronicMail>franz@mueller.de</cbc:ElectronicMail>
+      </cac:Contact>
+    </cac:Party>
+  </cac:AccountingCustomerParty>
+  <cac:Delivery>
+    <cbc:ActualDeliveryDate>2020-11-02</cbc:ActualDeliveryDate>
+    <cac:DeliveryLocation>
+      <cac:Address>
+        <cbc:StreetName>teststr.12a</cbc:StreetName>
+        <cbc:CityName>Entenhausen</cbc:CityName>
+        <cbc:PostalZone>55232</cbc:PostalZone>
+        <cac:Country>
+          <cbc:IdentificationCode>DE</cbc:IdentificationCode>
+        </cac:Country>
+      </cac:Address>
+    </cac:DeliveryLocation>
+    <cac:DeliveryParty>
+      <cac:PartyName>
+        <cbc:Name>just the other side of the street</cbc:Name>
+      </cac:PartyName>
+    </cac:DeliveryParty>
+  </cac:Delivery>
+  <cac:PaymentMeans>
+    <cbc:PaymentID>Verwendungszweck</cbc:PaymentID>
+  </cac:PaymentMeans>
+  <cac:PaymentTerms>
+    <cbc:Note>Please remit until 10.02.2025</cbc:Note>
+  </cac:PaymentTerms>
+  <cac:AllowanceCharge>
+    <cbc:ChargeIndicator>false</cbc:ChargeIndicator>
+    <cbc:AllowanceChargeReason>discount</cbc:AllowanceChargeReason>
+    <cbc:Amount currencyID="CHF">0.20</cbc:Amount>
+    <cac:TaxCategory>
+      <cbc:ID>S</cbc:ID>
+      <cbc:Percent>16.00</cbc:Percent>
+      <cac:TaxScheme>
+        <cbc:ID>VAT</cbc:ID>
+      </cac:TaxScheme>
+    </cac:TaxCategory>
+  </cac:AllowanceCharge>
+  <cac:AllowanceCharge>
+    <cbc:ChargeIndicator>true</cbc:ChargeIndicator>
+    <cbc:AllowanceChargeReason>quick delivery charge</cbc:AllowanceChargeReason>
+    <cbc:Amount currencyID="CHF">0.50</cbc:Amount>
+    <cac:TaxCategory>
+      <cbc:ID>S</cbc:ID>
+      <cbc:Percent>16.00</cbc:Percent>
+      <cac:TaxScheme>
+        <cbc:ID>VAT</cbc:ID>
+      </cac:TaxScheme>
+    </cac:TaxCategory>
+  </cac:AllowanceCharge>
+  <cac:TaxTotal>
+    <cbc:TaxAmount currencyID="CHF">0.20</cbc:TaxAmount>
+    <cac:TaxSubtotal>
+      <cbc:TaxableAmount currencyID="CHF">1.28</cbc:TaxableAmount>
+      <cbc:TaxAmount currencyID="CHF">0.20</cbc:TaxAmount>
+      <cac:TaxCategory>
+        <cbc:ID>S</cbc:ID>
+        <cbc:Percent>16.00</cbc:Percent>
+        <cac:TaxScheme>
+          <cbc:ID>VAT</cbc:ID>
+        </cac:TaxScheme>
+      </cac:TaxCategory>
+    </cac:TaxSubtotal>
+  </cac:TaxTotal>
+  <cac:LegalMonetaryTotal>
+    <cbc:LineExtensionAmount currencyID="CHF">0.98</cbc:LineExtensionAmount>
+    <cbc:TaxExclusiveAmount currencyID="CHF">1.28</cbc:TaxExclusiveAmount>
+    <cbc:TaxInclusiveAmount currencyID="CHF">1.48</cbc:TaxInclusiveAmount>
+    <cbc:AllowanceTotalAmount currencyID="CHF">0.20</cbc:AllowanceTotalAmount>
+    <cbc:ChargeTotalAmount currencyID="CHF">0.50</cbc:ChargeTotalAmount>
+    <cbc:PayableAmount currencyID="CHF">1.48</cbc:PayableAmount>
+  </cac:LegalMonetaryTotal>
+  <cac:InvoiceLine>
+    <cbc:ID>a123</cbc:ID>
+    <cbc:Note>item level 1/1</cbc:Note>
+    <cbc:InvoicedQuantity unitCode="H87">1.00000000</cbc:InvoicedQuantity>
+    <cbc:LineExtensionAmount currencyID="CHF">0.98</cbc:LineExtensionAmount>
+    <cac:InvoicePeriod>
+      <cbc:StartDate>2020-01-13</cbc:StartDate>
+      <cbc:EndDate>2020-01-15</cbc:EndDate>
+    </cac:InvoicePeriod>
+    <cac:OrderLineReference>
+      <cbc:LineID>xxx</cbc:LineID>
+    </cac:OrderLineReference>
+    <cac:Item>
+      <cbc:Name>Testprodukt</cbc:Name>
+      <cac:SellersItemIdentification>
+        <cbc:ID>4711</cbc:ID>
+      </cac:SellersItemIdentification>
+      <cac:StandardItemIdentification>
+        <cbc:ID schemeID="0160">2001015001325</cbc:ID>
+      </cac:StandardItemIdentification>
+      <cac:ClassifiedTaxCategory>
+        <cbc:ID>S</cbc:ID>
+        <cbc:Percent>16.00</cbc:Percent>
+        <cac:TaxScheme>
+          <cbc:ID>VAT</cbc:ID>
+        </cac:TaxScheme>
+      </cac:ClassifiedTaxCategory>
+    </cac:Item>
+    <cac:Price>
+      <cbc:PriceAmount currencyID="CHF">0.98</cbc:PriceAmount>
+      <cbc:BaseQuantity unitCode="H87">1.00</cbc:BaseQuantity>
+      <cac:AllowanceCharge>
+        <cbc:ChargeIndicator>false</cbc:ChargeIndicator>
+        <cbc:Amount currencyID="CHF">0.0200</cbc:Amount>
+        <cbc:BaseAmount currencyID="CHF">1.0000</cbc:BaseAmount>
+      </cac:AllowanceCharge>
+    </cac:Price>
+  </cac:InvoiceLine>
+</Invoice>