diff --git a/htdocs/comm/propal/card.php b/htdocs/comm/propal/card.php
index 72eee9c22df..b5f05e72795 100644
--- a/htdocs/comm/propal/card.php
+++ b/htdocs/comm/propal/card.php
@@ -1974,6 +1974,21 @@ if ($action == 'create') {
 			$text .= $notify->confirmMessage('PROPAL_VALIDATE', $object->socid, $object);
 		}
 
+		// mandatoryPeriod
+		$nbMandated = 0;
+		foreach ($object->lines as $line) {
+			$res = $line->fetch_product();
+			if ($res  > 0  ) {
+				if ($line->product->isService() && $line->product->isMandatoryPeriod() && (empty($line->date_start) || empty($line->date_end) )) {
+					$nbMandated++;
+					break;
+				}
+			}
+		}
+		if ($nbMandated > 0) {
+			$text .= '<div><span class="clearboth nowraponall warning">'.$langs->trans("mandatoryPeriodNeedTobeSetMsgValidate").'</span></div>';
+		}
+
 		if (!$error) {
 			$formconfirm = $form->formconfirm($_SERVER["PHP_SELF"].'?id='.$object->id, $langs->trans('ValidateProp'), $text, 'confirm_validate', '', 0, 1);
 		}
diff --git a/htdocs/commande/card.php b/htdocs/commande/card.php
index e1896cc48b6..decabedc2e8 100644
--- a/htdocs/commande/card.php
+++ b/htdocs/commande/card.php
@@ -1924,6 +1924,21 @@ if ($action == 'create' && $usercancreate) {
 				);
 			}
 
+			// mandatoryPeriod
+			$nbMandated = 0;
+			foreach ($object->lines as $line) {
+				$res = $line->fetch_product();
+				if ($res  > 0  ) {
+					if ($line->product->isService() && $line->product->isMandatoryPeriod() && (empty($line->date_start) || empty($line->date_end) )) {
+						$nbMandated++;
+						break;
+					}
+				}
+			}
+			if ($nbMandated > 0 ) $text .= '<div><span class="clearboth nowraponall warning">'.$langs->trans("mandatoryPeriodNeedTobeSetMsgValidate").'</span></div>';
+
+
+
 			$formconfirm = $form->formconfirm($_SERVER["PHP_SELF"].'?id='.$object->id, $langs->trans('ValidateOrder'), $text, 'confirm_validate', $formquestion, 0, 1, 220);
 		}
 
diff --git a/htdocs/compta/facture/card.php b/htdocs/compta/facture/card.php
index d4cf0a68441..7ddb90cd4da 100644
--- a/htdocs/compta/facture/card.php
+++ b/htdocs/compta/facture/card.php
@@ -4013,6 +4013,21 @@ if ($action == 'create') {
 		if ($object->type != Facture::TYPE_CREDIT_NOTE && $object->total_ttc < 0) { 		// Can happen only if $conf->global->FACTURE_ENABLE_NEGATIVE is on
 			$text .= '<br>'.img_warning().' '.$langs->trans("ErrorInvoiceOfThisTypeMustBePositive");
 		}
+
+		// mandatoryPeriod
+		$nbMandated = 0;
+		foreach ($object->lines as $line) {
+			$res = $line->fetch_product();
+			if ($res  > 0  ) {
+				if ($line->product->isService() && $line->product->isMandatoryPeriod() && (empty($line->date_start) || empty($line->date_end) )) {
+					$nbMandated++;
+					break;
+				}
+			}
+		}
+		if ($nbMandated > 0 ) $text .= '<div><span class="clearboth nowraponall warning">'.$langs->trans("mandatoryPeriodNeedTobeSetMsgValidate").'</span></div>';
+
+
 		$formconfirm = $form->formconfirm($_SERVER["PHP_SELF"].'?facid='.$object->id, $langs->trans('ValidateBill'), $text, 'confirm_valid', $formquestion, (($object->type != Facture::TYPE_CREDIT_NOTE && $object->total_ttc < 0) ? "no" : "yes"), 2);
 	}
 
diff --git a/htdocs/core/tpl/objectline_create.tpl.php b/htdocs/core/tpl/objectline_create.tpl.php
index f978a436354..d9ca8291066 100644
--- a/htdocs/core/tpl/objectline_create.tpl.php
+++ b/htdocs/core/tpl/objectline_create.tpl.php
@@ -68,6 +68,7 @@ if (!empty($conf->multicurrency->enabled) && $this->multicurrency_code != $conf-
 if (in_array($object->element, array('propal', 'commande', 'order', 'facture', 'facturerec', 'invoice', 'supplier_proposal', 'order_supplier', 'invoice_supplier'))) {
 	$colspan++; // With this, there is a column move button
 }
+
 //print $object->element;
 // Lines for extrafield
 $objectline = null;
@@ -675,13 +676,26 @@ if (!empty($usemargins) && $user->rights->margins->creer) {
 	}
 	?>
 
+<?php if ($this->table_element_line != 'commande_fournisseurdet') { ?>
+	$("#date_start, #date_end").focusout(function()
+	{
+		let  	type = $(this).attr('type');
+		let 	mandatoryP = $(this).attr('mandatoryperiod');
+		if (type == 1 && mandatoryP == 1 ){
+			if ( $(this).val() == ''  && !$(this).hasClass("error") ) {
+				$(this).addClass('error');
+			}else{
+				$(this).removeClass('error');
+			}
+		}
+	});
+<?php } ?>
 	/* When changing predefined product, we reload list of supplier prices required for margin combo */
 	$("#idprod, #idprodfournprice").change(function()
 	{
 		console.log("Call method change() after change on #idprod or #idprodfournprice (senderissupplier=<?php echo $senderissupplier; ?>). this.val = "+$(this).val());
 
 		setforpredef();		// TODO Keep vat combo visible and set it to first entry into list that match result of get_default_tva
-
 		jQuery('#trlinefordates').show();
 
 		<?php
@@ -703,6 +717,26 @@ if (!empty($usemargins) && $user->rights->margins->creer) {
 					{ 'id': $(this).val(), 'socid': <?php print $object->socid; ?> },
 					function(data) {
 						console.log("Load unit price end, we got value "+data.price_ht);
+
+							$( '#date_start').removeAttr( "type" );
+							$( '#date_end' ).removeAttr( "type" );
+							$('#date_start').attr('type', data.type);
+							$('#date_end').attr('type', data.type);
+
+							$( '#date_start').removeAttr( "mandatoryperiod" );
+							$( '#date_end' ).removeAttr( "mandatoryperiod" );
+							$('#date_start').attr('mandatoryperiod', data.mandatory_period);
+							$('#date_end').attr('mandatoryperiod', data.mandatory_period);
+
+						//  service and we setted mandatory_period to true
+						if (data.mandatory_period == 1 && data.type == 1 ) {
+							jQuery("#date_start").addClass("error");
+							jQuery("#date_end").addClass("error");
+						}else{
+							jQuery("#date_start").removeClass("error");
+							jQuery("#date_end").removeClass("error");
+						}
+
 						jQuery("#price_ht").val(data.price_ht);
 						<?php
 						if (!empty($conf->global->PRODUIT_AUTOFILL_DESC) && $conf->global->PRODUIT_AUTOFILL_DESC == 1) {
@@ -984,6 +1018,7 @@ if (!empty($usemargins) && $user->rights->margins->creer) {
 		jQuery("#np_marginRate, #np_markRate, .np_marginRate, .np_markRate, #units, #title_units").show();
 		jQuery("#fournprice_predef").hide();
 	}
+
 	function setforpredef() {
 		console.log("Call setforpredef. We hide some fields and show dates");
 		jQuery("#select_type").val(-1);
diff --git a/htdocs/core/tpl/objectline_edit.tpl.php b/htdocs/core/tpl/objectline_edit.tpl.php
index 9094daaa2d1..e15c489a5b6 100644
--- a/htdocs/core/tpl/objectline_edit.tpl.php
+++ b/htdocs/core/tpl/objectline_edit.tpl.php
@@ -333,9 +333,18 @@ $coldisplay++;
 		if (isset($conf->global->MAIN_DEFAULT_DATE_START_HOUR)) {
 			print 'jQuery("#date_starthour").val("'.$conf->global->MAIN_DEFAULT_DATE_START_HOUR.'");';
 		}
+
+
 		if (isset($conf->global->MAIN_DEFAULT_DATE_START_MIN)) {
 			print 'jQuery("#date_startmin").val("'.$conf->global->MAIN_DEFAULT_DATE_START_MIN.'");';
 		}
+
+		$res = $line->fetch_product();
+		if ($res  > 0  ) {
+			if ( $line->product->isMandatoryPeriod() && $line->product->isService()) {
+				print  'jQuery("#date_start").addClass("error");';
+			}
+		}
 	}
 	if (!$line->date_end) {
 		if (isset($conf->global->MAIN_DEFAULT_DATE_END_HOUR)) {
@@ -344,6 +353,14 @@ $coldisplay++;
 		if (isset($conf->global->MAIN_DEFAULT_DATE_END_MIN)) {
 			print 'jQuery("#date_endmin").val("'.$conf->global->MAIN_DEFAULT_DATE_END_MIN.'");';
 		}
+
+		$res = $line->fetch_product();
+		// on doit fetch le product là !!! pour connaître le type
+		if ($res  > 0  ) {
+			if ($line->product->isMandatoryperiod() && $line->product->isService()) {
+				print  'jQuery("#date_end").addClass("error");';
+			}
+		}
 	}
 	print '</script>'
 	?>
@@ -451,6 +468,15 @@ jQuery(document).ready(function()
 		}
 	});
 
+	$("#date_start, #date_end").focusout(function()
+	{
+
+		if ( $(this).val() == ''  && !$(this).hasClass("error") ) {
+			$(this).addClass('error');
+		}else{
+			$(this).removeClass('error');
+		}
+	});
 	<?php
 	if (!empty($conf->margin->enabled)) {
 		?>
diff --git a/htdocs/core/tpl/objectline_view.tpl.php b/htdocs/core/tpl/objectline_view.tpl.php
index ad27dae210c..8ebb767a4d8 100644
--- a/htdocs/core/tpl/objectline_view.tpl.php
+++ b/htdocs/core/tpl/objectline_view.tpl.php
@@ -182,6 +182,22 @@ if (($line->info_bits & 2) == 2) {
 		if ($line->date_start || $line->date_end) {
 			print '<div class="clearboth nowraponall opacitymedium daterangeofline">'.get_date_range($line->date_start, $line->date_end, $format).'</div>';
 		}
+		if (!$line->date_start || !$line->date_end) {
+			// show warning under line
+			// we need to fetch product associated to line for some test
+			if ($object->element == 'propal'  || $object->element == 'order' || $object->element == 'propal_supplier' || $object->element == 'supplier_proposal' || $object->element == 'commande') {
+				$res = $line->fetch_product();
+				if ($res  > 0  ) {
+					if ($line->product->isService() && $line->product->isMandatoryPeriod()) {
+						print '<div><span class="clearboth nowraponall warning">'.$langs->trans("mandatoryPeriodNeedTobeSet").'</span></div>';
+					}
+				}
+			}
+		}
+
+
+
+
 		//print get_date_range($line->date_start, $line->date_end, $format);
 	}
 
diff --git a/htdocs/install/mysql/migration/14.0.0-15.0.0.sql b/htdocs/install/mysql/migration/14.0.0-15.0.0.sql
index fb0969dc7ef..f4f6e9e349f 100644
--- a/htdocs/install/mysql/migration/14.0.0-15.0.0.sql
+++ b/htdocs/install/mysql/migration/14.0.0-15.0.0.sql
@@ -57,6 +57,7 @@ INSERT INTO llx_c_email_templates (entity, module, type_template, lang, private,
 
 
 -- v15
+ALTER TABLE llx_product ADD COLUMN mandatory_period tinyint NULL DEFAULT 0;
 
 ALTER TABLE llx_holiday ADD COLUMN date_approve   DATETIME DEFAULT NULL;
 ALTER TABLE llx_holiday ADD COLUMN fk_user_approve integer DEFAULT NULL;
diff --git a/htdocs/install/mysql/tables/llx_product.sql b/htdocs/install/mysql/tables/llx_product.sql
index e89a7658e5a..463ed33a86e 100644
--- a/htdocs/install/mysql/tables/llx_product.sql
+++ b/htdocs/install/mysql/tables/llx_product.sql
@@ -103,6 +103,9 @@ create table llx_product
   desiredstock                  float      DEFAULT 0,
   fk_unit                       integer      DEFAULT NULL,
   price_autogen                 tinyint      DEFAULT 0,
+  fk_project                    integer      DEFAULT NULL,           -- Used when product was generated by a project or is specifif to a project
+  mandatory_period              tinyint      DEFAULT 0               -- is used to signal to the user that the start and end dates are mandatory for this type of product the fk_product_type == 1 (service) (non-blocking action)
+
   fk_default_bom                integer      DEFAULT NULL,
   fk_project                    integer      DEFAULT NULL           -- Used when the product was generated by a project or is specific to a project
 )ENGINE=innodb;
diff --git a/htdocs/langs/en_US/products.lang b/htdocs/langs/en_US/products.lang
index 294e2afbc03..128eb120e0b 100644
--- a/htdocs/langs/en_US/products.lang
+++ b/htdocs/langs/en_US/products.lang
@@ -401,5 +401,11 @@ DeleteLinkedProduct=Delete the child product linked to the combination
 AmountUsedToUpdateWAP=Amount to use to update the Weighted Average Price
 PMPValue=Weighted average price
 PMPValueShort=WAP
+
+mandatoryperiod=Mandatory periods
+mandatoryPeriodNeedTobeSet=Attention periods not entered and mandatory
+mandatoryPeriodNeedTobeSetMsgValidate=A service requires a start and end period
+mandatoryHelper=Message to the user on the need to enter a start date and an end date on a service when creating / validating an invoice, commercial proposal, sales order. <br> This action is not blocking in the process of confirmation
 DefaultBOM=Default BOM
-DefaultBOMDesc=The default BOM recommended to use to manufacture this product. This field can be set only if nature of product is '%s'. 
\ No newline at end of file
+DefaultBOMDesc=The default BOM recommended to use to manufacture this product. This field can be set only if nature of product is '%s'. 
+
diff --git a/htdocs/langs/fr_FR/products.lang b/htdocs/langs/fr_FR/products.lang
index 013d75d2ec0..83514bd95ff 100644
--- a/htdocs/langs/fr_FR/products.lang
+++ b/htdocs/langs/fr_FR/products.lang
@@ -399,3 +399,7 @@ ProductSupplierExtraFields=Attributs supplémentaires (Prix fournisseur)
 DeleteLinkedProduct=Supprimer le produit enfant lié à la combinaison
 PMPValue=Prix moyen pondéré (PMP)
 PMPValueShort=PMP
+mandatoryperiod=Périodes obligatoires
+mandatoryPeriodNeedTobeSet=Attention périodes non saisies et obligatoires
+mandatoryPeriodNeedTobeSetMsgValidate=Un service nécessite une période de début et de fin
+mandatoryHelper=Message à l'utilisateur sur la necessité de saisir une date de début et une date de fin sur un service lors de la création/validation  de facture, proposition commerciale , commande client.<br>Cette action n'est pas bloquante dans le processus de validation
diff --git a/htdocs/product/ajax/products.php b/htdocs/product/ajax/products.php
index 77acafbbd55..9ba8d9cec09 100644
--- a/htdocs/product/ajax/products.php
+++ b/htdocs/product/ajax/products.php
@@ -91,7 +91,7 @@ if (!empty($action) && $action == 'fetch' && !empty($id)) {
 		$outtype = $object->type;
 		$outqty = 1;
 		$outdiscount = 0;
-
+		$mandatory_period = $object->mandatory_period;
 		$found = false;
 
 		$price_level = 1;
@@ -203,6 +203,7 @@ if (!empty($action) && $action == 'fetch' && !empty($id)) {
 			'tva_tx' => $outtva_tx,
 			'qty' => $outqty,
 			'discount' => $outdiscount,
+			'mandatory_period' => $mandatory_period,
 			'array_options'=>$object->array_options);
 	}
 
diff --git a/htdocs/product/card.php b/htdocs/product/card.php
index b6820bddddd..9e7a9b6d52d 100644
--- a/htdocs/product/card.php
+++ b/htdocs/product/card.php
@@ -105,6 +105,7 @@ $accountancy_code_buy = GETPOST('accountancy_code_buy', 'alpha');
 $accountancy_code_buy_intra = GETPOST('accountancy_code_buy_intra', 'alpha');
 $accountancy_code_buy_export = GETPOST('accountancy_code_buy_export', 'alpha');
 
+$checkmandatory = GETPOST('accountancy_code_buy_export', 'alpha');
 // by default 'alphanohtml' (better security); hidden conf MAIN_SECURITY_ALLOW_UNSECURED_LABELS_WITH_HTML allows basic html
 $label_security_check = empty($conf->global->MAIN_SECURITY_ALLOW_UNSECURED_LABELS_WITH_HTML) ? 'alphanohtml' : 'restricthtml';
 
@@ -298,7 +299,7 @@ if (empty($reshook)) {
 			$object->ref                   = $ref;
 			$object->label                 = GETPOST('label', $label_security_check);
 			$object->price_base_type       = GETPOST('price_base_type', 'aZ09');
-
+			$object->mandatory_period 	   = !empty(GETPOST("mandatoryperiod", 'alpha')) ? 1 : 0;
 			if ($object->price_base_type == 'TTC') {
 				$object->price_ttc = GETPOST('price');
 			} else {
@@ -599,7 +600,7 @@ if (empty($reshook)) {
 				$accountancy_code_buy = GETPOST('accountancy_code_buy', 'alpha');
 				$accountancy_code_buy_intra = GETPOST('accountancy_code_buy_intra', 'alpha');
 				$accountancy_code_buy_export = GETPOST('accountancy_code_buy_export', 'alpha');
-
+				$checkmandatory = GETPOST('mandatoryperiod', 'alpha');
 				if (empty($accountancy_code_sell) || $accountancy_code_sell == '-1') {
 					$object->accountancy_code_sell = '';
 				} else {
@@ -630,6 +631,11 @@ if (empty($reshook)) {
 				} else {
 					$object->accountancy_code_buy_export = $accountancy_code_buy_export;
 				}
+				if ($object->isService()) {
+					$object->mandatory_period =  (!empty($checkmandatory)) ? 1 : 0 ;
+				}
+
+
 
 				// Fill array 'array_options' with data from add form
 				$ret = $extrafields->setOptionalsFromPost(null, $object);
@@ -1446,6 +1452,14 @@ if (is_object($objcanvas) && $objcanvas->displayCanvasExists($action)) {
 				print $form->load_tva("tva_tx", $defaultva, $mysoc, $mysoc, 0, 0, '', false, 1);
 				print '</td></tr>';
 
+				if (!empty($conf->service->enabled)) {
+					if ($object->isService()) {
+						// Mandatory period
+						print '<tr><td class="titlefieldcreate">'.$langs->trans("mandatoryperiod").'</td>';
+						print '<td><input type="checkbox" name="mandatoryperiod" /> ';
+						print '</td></tr>';
+					}
+				}
 				print '</table>';
 
 				print '<br>';
@@ -2036,6 +2050,13 @@ if (is_object($objcanvas) && $objcanvas->displayCanvasExists($action)) {
 					print '<tr><td class="titlefieldcreate">'.$langs->trans("ProductAccountancyBuyExportCode").'</td>';
 					print '<td><input name="accountancy_code_buy_export" class="maxwidth200" value="'.$object->accountancy_code_buy_export.'">';
 					print '</td></tr>';
+
+					if ($object->isService()) {
+						// Mandatory period
+						print '<tr><td class="titlefieldcreate">'.$langs->trans("mandatoryperiod").'</td>';
+						print '<td><input type="checkbox" name="mandatoryperiod"'.($object->mandatory_period == 1 ? ' checked="checked"' : '').' /> ';
+						print '</td></tr>';
+					}
 				}
 			}
 			print '</table>';
@@ -2310,6 +2331,13 @@ if (is_object($objcanvas) && $objcanvas->displayCanvasExists($action)) {
 				print (!empty($object->duration_unit) && isset($dur[$object->duration_unit]) ? $langs->trans($dur[$object->duration_unit]) : '')."&nbsp;";
 
 				print '</td></tr>';
+
+				// Mandatory period
+				$htmltooltip = '<br>'.$langs->trans("mandatoryHelper");
+				print '<tr><td class="titlefield">'.$langs->trans("mandatoryperiod");
+				print $form->textwithpicto('', $htmltooltip, 1, 0).'</td><td>';
+				print '<input type="checkbox" name="mandatoryperiod"'.($object->mandatory_period == 1 ? ' checked="checked"' : '').' disabled/> ';
+				print '</td></tr>';
 			} else {
 				if (empty($conf->global->PRODUCT_DISABLE_NATURE)) {
 					// Nature
diff --git a/htdocs/product/class/product.class.php b/htdocs/product/class/product.class.php
index b624c0f231e..fd5d8ecf1db 100644
--- a/htdocs/product/class/product.class.php
+++ b/htdocs/product/class/product.class.php
@@ -434,6 +434,13 @@ class Product extends CommonObject
 	public $is_object_used;
 
 
+	/**
+	 *
+	 *
+	 *
+	 */
+	 public $mandatory_period;
+
 	/**
 	 *  'type' if the field format ('integer', 'integer:ObjectClass:PathToClass[:AddCreateButtonOrNot[:Filter]]', 'varchar(x)', 'double(24,8)', 'real', 'price', 'text', 'html', 'date', 'datetime', 'timestamp', 'duration', 'mail', 'phone', 'url', 'password')
 	 *         Note: Filter can be a string like "(t.ref:like:'SO-%') or (t.date_creation:<:'20160101') or (t.nature:is:NULL)"
@@ -484,6 +491,8 @@ class Product extends CommonObject
 		'import_key'    =>array('type'=>'varchar(14)', 'label'=>'ImportId', 'enabled'=>1, 'visible'=>-2, 'notnull'=>-1, 'index'=>0, 'position'=>1000),
 		//'tosell'       =>array('type'=>'integer',      'label'=>'Status',           'enabled'=>1, 'visible'=>1,  'notnull'=>1, 'default'=>0, 'index'=>1,  'position'=>1000, 'arrayofkeyval'=>array(0=>'Draft', 1=>'Active', -1=>'Cancel')),
 		//'tobuy'        =>array('type'=>'integer',      'label'=>'Status',           'enabled'=>1, 'visible'=>1,  'notnull'=>1, 'default'=>0, 'index'=>1,  'position'=>1000, 'arrayofkeyval'=>array(0=>'Draft', 1=>'Active', -1=>'Cancel')),
+		'mandatory_period'        =>array('type'=>'integer', 'label'=>'mandatory_period', 'enabled'=>1, 'visible'=>1,  'notnull'=>1, 'default'=>0, 'index'=>1,  'position'=>1000),
+
 	);
 
 	/**
@@ -635,7 +644,7 @@ class Product extends CommonObject
 
 		// Barcode value
 		$this->barcode = trim($this->barcode);
-
+		$this->mandatory_period = empty($this->mandatory_period) ? 0 : $this->mandatory_period;
 		// Check parameters
 		if (empty($this->label)) {
 			$this->error = 'ErrorMandatoryParametersNotProvided';
@@ -717,6 +726,7 @@ class Product extends CommonObject
 					$sql .= ", tobatch";
 					$sql .= ", batch_mask";
 					$sql .= ", fk_unit";
+					$sql .= ", mandatory_period";
 					$sql .= ") VALUES (";
 					$sql .= "'".$this->db->idate($now)."'";
 					$sql .= ", ".((int) $conf->entity);
@@ -745,6 +755,7 @@ class Product extends CommonObject
 					$sql .= ", ".((empty($this->status_batch) || $this->status_batch < 0) ? '0' : ((int) $this->status_batch));
 					$sql .= ", '".$this->db->escape($this->batch_mask)."'";
 					$sql .= ", ".($this->fk_unit > 0 ? ((int) $this->fk_unit) : 'NULL');
+					$sql .= ", '".$this->db->escape($this->mandatory_period)."'";
 					$sql .= ")";
 
 					dol_syslog(get_class($this)."::Create", LOG_DEBUG);
@@ -1149,7 +1160,7 @@ class Product extends CommonObject
 			$sql .= ", price_autogen = ".(!$this->price_autogen ? 0 : 1);
 			$sql .= ", fk_price_expression = ".($this->fk_price_expression != 0 ? (int) $this->fk_price_expression : 'NULL');
 			$sql .= ", fk_user_modif = ".($user->id > 0 ? $user->id : 'NULL');
-
+			$sql .= ", mandatory_period = ".($this->mandatory_period );
 			// stock field is not here because it is a denormalized value from product_stock.
 			$sql .= " WHERE rowid = ".((int) $id);
 
@@ -2252,7 +2263,7 @@ class Product extends CommonObject
 		$sql .= " p.price_min, p.price_min_ttc, p.price_base_type, p.cost_price, p.default_vat_code, p.tva_tx, p.recuperableonly as tva_npr, p.localtax1_tx, p.localtax2_tx, p.localtax1_type, p.localtax2_type, p.tosell,";
 		$sql .= " p.tobuy, p.fk_product_type, p.duration, p.fk_default_warehouse, p.seuil_stock_alerte, p.canvas, p.net_measure, p.net_measure_units, p.weight, p.weight_units,";
 		$sql .= " p.length, p.length_units, p.width, p.width_units, p.height, p.height_units,";
-		$sql .= " p.surface, p.surface_units, p.volume, p.volume_units, p.barcode, p.fk_barcode_type, p.finished, p.fk_default_bom,";
+		$sql .= " p.surface, p.surface_units, p.volume, p.volume_units, p.barcode, p.fk_barcode_type, p.finished, p.fk_default_bom, p.mandatory_period,";
 		if (empty($conf->global->MAIN_PRODUCT_PERENTITY_SHARED)) {
 			$sql .= " p.accountancy_code_buy, p.accountancy_code_buy_intra, p.accountancy_code_buy_export, p.accountancy_code_sell, p.accountancy_code_sell_intra, p.accountancy_code_sell_export,";
 		} else {
@@ -2427,6 +2438,8 @@ class Product extends CommonObject
 				$this->price_autogen = $obj->price_autogen;
 				$this->model_pdf = $obj->model_pdf;
 
+				$this->mandatory_period = $obj->mandatory_period;
+
 				$this->db->free($resql);
 
 				// fetch optionals attributes and labels
@@ -5642,6 +5655,16 @@ class Product extends CommonObject
 		return ($this->type == Product::TYPE_SERVICE ? true : false);
 	}
 
+
+	/**
+	 * Return if  object have a constraint on mandatory_period
+	 *
+	 * @return boolean     True if mandatory_period setted to 1
+	 */
+	public function isMandatoryPeriod()
+	{
+		return ($this->mandatory_period == 1 ? true : false);
+	}
 	// phpcs:disable PEAR.NamingConventions.ValidFunctionName.ScopeNotCamelCaps
 	/**
 	 *  Get a barcode from the module to generate barcode values.