diff --git a/admin/meta-box-project-details.php b/admin/meta-box-project-details.php
index a0ec852..6bdcdfe 100644
--- a/admin/meta-box-project-details.php
+++ b/admin/meta-box-project-details.php
@@ -29,6 +29,36 @@
 
 $hourly_rate = get_post_meta( $post->ID, '_orbis_hourly_rate', true );
 
+$start_date = null;
+
+$start_date_string = \get_post_meta( $post->ID, '_orbis_project_start_date', true );
+
+if ( '' !== $start_date_string ) {
+	$value = DateTimeImmutable::createFromFormat( 'Y-m-d', $start_date_string );
+
+	$start_date = ( false === $value ) ? null : $value->setTime( 0, 0 );
+}
+
+$end_date = null;
+
+$end_date_string = \get_post_meta( $post->ID, '_orbis_project_end_date', true );
+
+if ( '' !== $end_date_string ) {
+	$value = DateTimeImmutable::createFromFormat( 'Y-m-d', $end_date_string );
+
+	$end_date = ( false === $value ) ? null : $value->setTime( 0, 0 );
+}
+
+$billed_to = null;
+
+$billed_to_string = \get_post_meta( $post->ID, '_orbis_project_billed_to', true );
+
+if ( '' !== $billed_to_string ) {
+	$value = DateTimeImmutable::createFromFormat( 'Y-m-d', $billed_to_string );
+
+	$billed_to = ( false === $value ) ? null : $value->setTime( 0, 0 );
+}
+
 ?>
 <table class="form-table">
 	<tbody>
@@ -189,6 +219,53 @@
 			</td>
 		</tr>
 		<?php endif; ?>
+
+		<tr valign="top">
+			<th scope="row">
+				<label for="orbis_project_start_date"><?php esc_html_e( 'Period', 'orbis-tasks' ); ?></label>
+			</th>
+			<td>
+				<?php
+
+				echo \wp_kses(
+					\sprintf(
+						/**
+						 * The 'to' includes the end date, in Dutch it is translated as 'tot en met'.
+						 *
+						 * @link https://taaladvies.net/tot-of-tot-en-met/
+						 */
+						/* translators: 1: input for start date, 2: input for end date */
+						_x( '%1$s to %2$s', 'including', 'orbis-projects' ),
+						\sprintf( 
+							'<input id="orbis_project_start_date" name="_orbis_project_start_date" value="%s" type="date" />',
+							\esc_attr( null === $start_date ? '' : $start_date->format( 'Y-m-d' ) )
+						),
+						\sprintf(
+							'<input id="orbis_project_end_date" name="_orbis_project_end_date" value="%s" type="date" />',
+							esc_attr( null === $end_date ? '' : $end_date->format( 'Y-m-d' ) )
+						)
+					),
+					[
+						'input' => [
+							'id'    => true,
+							'name'  => true,
+							'value' => true,
+							'type'  => true,
+						],
+					]
+				);
+
+				?>
+			</td>
+		</tr>
+		<tr>
+			<th scope="row">
+				<label for="orbis_project_billed_to"><?php echo esc_html( _x( 'Billed to', 'including', 'orbis-projects' ) ); ?></label>
+			</th>
+			<td>
+				<input id="orbis_project_billed_to" name="_orbis_project_billed_to" value="<?php echo esc_attr( null === $billed_to ? '' : $billed_to->format( 'Y-m-d' ) ); ?>" type="date" />
+			</td>
+		</tr>
 	</tbody>
 </table>
 
diff --git a/classes/AdminProjectPostType.php b/classes/AdminProjectPostType.php
index 5bbe2e8..534e416 100644
--- a/classes/AdminProjectPostType.php
+++ b/classes/AdminProjectPostType.php
@@ -180,6 +180,9 @@ public function save_project( $post_id, $post ) {
 			'_orbis_project_invoice_number'   => FILTER_SANITIZE_STRING,
 			'_orbis_invoice_reference'        => FILTER_SANITIZE_STRING,
 			'_orbis_invoice_line_description' => FILTER_SANITIZE_STRING,
+			'_orbis_project_start_date'       => FILTER_SANITIZE_STRING,
+			'_orbis_project_end_date'         => FILTER_SANITIZE_STRING,
+			'_orbis_project_billed_to'        => FILTER_SANITIZE_STRING,
 		];
 
 		if ( current_user_can( 'edit_orbis_project_administration' ) ) {
diff --git a/languages/orbis-projects-nl_NL.mo b/languages/orbis-projects-nl_NL.mo
index d469970..0035c1b 100644
Binary files a/languages/orbis-projects-nl_NL.mo and b/languages/orbis-projects-nl_NL.mo differ
diff --git a/languages/orbis-projects-nl_NL.po b/languages/orbis-projects-nl_NL.po
index e1e6ae5..7e607c2 100644
--- a/languages/orbis-projects-nl_NL.po
+++ b/languages/orbis-projects-nl_NL.po
@@ -4,8 +4,8 @@ msgid ""
 msgstr ""
 "Project-Id-Version: Orbis Projects\n"
 "Report-Msgid-Bugs-To: https://wordpress.org/support/plugin/orbis-projects\n"
-"POT-Creation-Date: 2024-02-15T08:31:59+00:00\n"
-"PO-Revision-Date: 2024-02-15 09:32+0100\n"
+"POT-Creation-Date: 2024-02-15T19:23:22+00:00\n"
+"PO-Revision-Date: 2024-02-15 20:23+0100\n"
 "Last-Translator: Remco Tolsma <info@remcotolsma.nl>\n"
 "Language-Team: Pronamic <info@pronamic.eu>\n"
 "Language: nl_NL\n"
@@ -44,63 +44,63 @@ msgstr "Pronamic"
 msgid "https://www.pronamic.eu/"
 msgstr "https://www.pronamic.nl/"
 
-#: admin/meta-box-project-details.php:37 templates/projects-to-invoice.php:180
+#: admin/meta-box-project-details.php:67 templates/projects-to-invoice.php:180
 #: templates/projects-to-invoice.php:184
 #: templates/projects-without-agreement.php:29
 msgid "Orbis ID"
 msgstr "Orbis ID"
 
-#: admin/meta-box-project-details.php:45 templates/projects-table-view.php:33
+#: admin/meta-box-project-details.php:75 templates/projects-table-view.php:33
 msgid "Client"
 msgstr "Klant"
 
-#: admin/meta-box-project-details.php:48
+#: admin/meta-box-project-details.php:78
 msgid "Select Client"
 msgstr "Selecteer klant"
 
-#: admin/meta-box-project-details.php:57 classes/AdminProjectPostType.php:46
+#: admin/meta-box-project-details.php:87 classes/AdminProjectPostType.php:46
 msgid "Price"
 msgstr "Prijs"
 
-#: admin/meta-box-project-details.php:65
+#: admin/meta-box-project-details.php:95
 msgid "Hourly Rate"
 msgstr "Uurtarief"
 
-#: admin/meta-box-project-details.php:73 classes/AdminProjectPostType.php:47
+#: admin/meta-box-project-details.php:103 classes/AdminProjectPostType.php:47
 #: templates/projects-to-invoice.php:189 templates/projects-to-invoice.php:192
 #: templates/projects-to-invoice.php:198
 msgid "Time"
 msgstr "Tijd"
 
-#: admin/meta-box-project-details.php:79
+#: admin/meta-box-project-details.php:109
 msgid ""
 "You can enter time as 1.5 or 1:30 (they both mean 1 hour and 30 minutes)."
 msgstr ""
 "Je kunt de tijd invoeren als 1.5 of 1:30 (beide zijn 1 uur en 30 minuten)."
 
-#: admin/meta-box-project-details.php:86
+#: admin/meta-box-project-details.php:116
 msgid "Agreement ID"
 msgstr "Akkoord ID"
 
-#: admin/meta-box-project-details.php:93
+#: admin/meta-box-project-details.php:123
 msgid "Choose an Agreement"
 msgstr "Kies een akkoord"
 
-#: admin/meta-box-project-details.php:96
+#: admin/meta-box-project-details.php:126
 msgid "Set as Agreement"
 msgstr "Stel in als akkoord"
 
-#: admin/meta-box-project-details.php:96
+#: admin/meta-box-project-details.php:126
 msgid "Choose a Agreement"
 msgstr "Kies een akkoord"
 
-#: admin/meta-box-project-details.php:99
+#: admin/meta-box-project-details.php:129
 msgid "You can select an .PDF or .TXT file from the WordPress media library."
 msgstr ""
 "Je kunt een .PDF of .TXT bestand selecteren uit de WordPress media "
 "bibliotheek."
 
-#: admin/meta-box-project-details.php:100
+#: admin/meta-box-project-details.php:130
 msgid ""
 "If you received the agreement by mail print the complete mail conversation "
 "with an PDF printer."
@@ -108,46 +108,57 @@ msgstr ""
 "Als je een akkoord per e-mail hebt ontvangen print dan de complete e-mail "
 "conversatie uit met een PDF-printer."
 
-#: admin/meta-box-project-details.php:107
+#: admin/meta-box-project-details.php:137
 msgid "Finished"
 msgstr "Afgerond"
 
-#: admin/meta-box-project-details.php:113
+#: admin/meta-box-project-details.php:143
 msgid "Project is finished"
 msgstr "Project is afgerond"
 
-#: admin/meta-box-project-details.php:121 templates/projects-table-view.php:45
+#: admin/meta-box-project-details.php:151 templates/projects-table-view.php:45
 msgid "Invoicable"
 msgstr "Factureerbaar"
 
-#: admin/meta-box-project-details.php:127
+#: admin/meta-box-project-details.php:157
 msgid "Project is invoicable"
 msgstr "Project is factureerbaar"
 
-#: admin/meta-box-project-details.php:137
+#: admin/meta-box-project-details.php:167
 msgid "Invoiced"
 msgstr "Gefactureerd"
 
-#: admin/meta-box-project-details.php:143
+#: admin/meta-box-project-details.php:173
 msgid "Project is invoiced"
 msgstr "Project is gefactureerd"
 
-#: admin/meta-box-project-details.php:152 templates/projects-table-view.php:105
+#: admin/meta-box-project-details.php:182 templates/projects-table-view.php:105
 msgid "Invoice reference"
 msgstr "Factuurreferentie"
 
-#: admin/meta-box-project-details.php:160
+#: admin/meta-box-project-details.php:190
 msgid "Invoice Line Description"
 msgstr "Factuurregelbeschrijving"
 
-#: admin/meta-box-project-details.php:175
+#: admin/meta-box-project-details.php:205
 msgid "Payment Method"
 msgstr "Betaalmethode"
 
-#: admin/meta-box-project-details.php:182
+#: admin/meta-box-project-details.php:212
 msgid "— Select Payment Method —"
 msgstr "— Selecteer betaalmethode —"
 
+#. translators: 1: input for start date, 2: input for end date
+#: admin/meta-box-project-details.php:238
+msgctxt "including"
+msgid "%1$s to %2$s"
+msgstr "%1$s t/m %2$s"
+
+#: admin/meta-box-project-details.php:263
+msgctxt "including"
+msgid "Billed to"
+msgstr "Gefactureerd t/m"
+
 #: admin/meta-box-project-invoices.php:17 classes/AdminProjectPostType.php:50
 #: templates/project-invoices.php:16 templates/projects-table-view.php:42
 msgid "Date"
diff --git a/languages/orbis-projects.pot b/languages/orbis-projects.pot
index dbee274..414e119 100644
--- a/languages/orbis-projects.pot
+++ b/languages/orbis-projects.pot
@@ -9,7 +9,7 @@ msgstr ""
 "MIME-Version: 1.0\n"
 "Content-Type: text/plain; charset=UTF-8\n"
 "Content-Transfer-Encoding: 8bit\n"
-"POT-Creation-Date: 2024-02-15T08:31:59+00:00\n"
+"POT-Creation-Date: 2024-02-15T19:23:22+00:00\n"
 "PO-Revision-Date: YEAR-MO-DA HO:MI+ZONE\n"
 "X-Generator: WP-CLI 2.10.0\n"
 "X-Domain: orbis-projects\n"
@@ -39,32 +39,32 @@ msgstr ""
 msgid "https://www.pronamic.eu/"
 msgstr ""
 
-#: admin/meta-box-project-details.php:37
+#: admin/meta-box-project-details.php:67
 #: templates/projects-to-invoice.php:180
 #: templates/projects-to-invoice.php:184
 #: templates/projects-without-agreement.php:29
 msgid "Orbis ID"
 msgstr ""
 
-#: admin/meta-box-project-details.php:45
+#: admin/meta-box-project-details.php:75
 #: templates/projects-table-view.php:33
 msgid "Client"
 msgstr ""
 
-#: admin/meta-box-project-details.php:48
+#: admin/meta-box-project-details.php:78
 msgid "Select Client"
 msgstr ""
 
-#: admin/meta-box-project-details.php:57
+#: admin/meta-box-project-details.php:87
 #: classes/AdminProjectPostType.php:46
 msgid "Price"
 msgstr ""
 
-#: admin/meta-box-project-details.php:65
+#: admin/meta-box-project-details.php:95
 msgid "Hourly Rate"
 msgstr ""
 
-#: admin/meta-box-project-details.php:73
+#: admin/meta-box-project-details.php:103
 #: classes/AdminProjectPostType.php:47
 #: templates/projects-to-invoice.php:189
 #: templates/projects-to-invoice.php:192
@@ -72,76 +72,87 @@ msgstr ""
 msgid "Time"
 msgstr ""
 
-#: admin/meta-box-project-details.php:79
+#: admin/meta-box-project-details.php:109
 msgid "You can enter time as 1.5 or 1:30 (they both mean 1 hour and 30 minutes)."
 msgstr ""
 
-#: admin/meta-box-project-details.php:86
+#: admin/meta-box-project-details.php:116
 msgid "Agreement ID"
 msgstr ""
 
-#: admin/meta-box-project-details.php:93
+#: admin/meta-box-project-details.php:123
 msgid "Choose an Agreement"
 msgstr ""
 
-#: admin/meta-box-project-details.php:96
+#: admin/meta-box-project-details.php:126
 msgid "Set as Agreement"
 msgstr ""
 
-#: admin/meta-box-project-details.php:96
+#: admin/meta-box-project-details.php:126
 msgid "Choose a Agreement"
 msgstr ""
 
-#: admin/meta-box-project-details.php:99
+#: admin/meta-box-project-details.php:129
 msgid "You can select an .PDF or .TXT file from the WordPress media library."
 msgstr ""
 
-#: admin/meta-box-project-details.php:100
+#: admin/meta-box-project-details.php:130
 msgid "If you received the agreement by mail print the complete mail conversation with an PDF printer."
 msgstr ""
 
-#: admin/meta-box-project-details.php:107
+#: admin/meta-box-project-details.php:137
 msgid "Finished"
 msgstr ""
 
-#: admin/meta-box-project-details.php:113
+#: admin/meta-box-project-details.php:143
 msgid "Project is finished"
 msgstr ""
 
-#: admin/meta-box-project-details.php:121
+#: admin/meta-box-project-details.php:151
 #: templates/projects-table-view.php:45
 msgid "Invoicable"
 msgstr ""
 
-#: admin/meta-box-project-details.php:127
+#: admin/meta-box-project-details.php:157
 msgid "Project is invoicable"
 msgstr ""
 
-#: admin/meta-box-project-details.php:137
+#: admin/meta-box-project-details.php:167
 msgid "Invoiced"
 msgstr ""
 
-#: admin/meta-box-project-details.php:143
+#: admin/meta-box-project-details.php:173
 msgid "Project is invoiced"
 msgstr ""
 
-#: admin/meta-box-project-details.php:152
+#: admin/meta-box-project-details.php:182
 #: templates/projects-table-view.php:105
 msgid "Invoice reference"
 msgstr ""
 
-#: admin/meta-box-project-details.php:160
+#: admin/meta-box-project-details.php:190
 msgid "Invoice Line Description"
 msgstr ""
 
-#: admin/meta-box-project-details.php:175
+#: admin/meta-box-project-details.php:205
 msgid "Payment Method"
 msgstr ""
 
-#: admin/meta-box-project-details.php:182
+#: admin/meta-box-project-details.php:212
 msgid "— Select Payment Method —"
 msgstr ""
 
+#. translators: 1: input for start date, 2: input for end date
+#: admin/meta-box-project-details.php:238
+msgctxt "including"
+msgid "%1$s to %2$s"
+msgstr ""
+
+#: admin/meta-box-project-details.php:263
+msgctxt "including"
+msgid "Billed to"
+msgstr ""
+
 #: admin/meta-box-project-invoices.php:17
 #: classes/AdminProjectPostType.php:50
 #: templates/project-invoices.php:16