diff --git a/application/controllers/Logbook.php b/application/controllers/Logbook.php
index 748a0e0a8..8a2d61c68 100644
--- a/application/controllers/Logbook.php
+++ b/application/controllers/Logbook.php
@@ -685,9 +685,9 @@ class Logbook extends CI_Controller {
 			}
 
 			foreach ($query->result() as $row) {
-				$timestamp = strtotime($row->COL_TIME_ON);
+				$timestamp = strtotime($row->COL_TIME_ON ?? '1970-01-01 00:00:00');
 				$html .= "<tr>";
-					$html .= "<td>".date($custom_date_format, $timestamp). date(' H:i',strtotime($row->COL_TIME_ON)) . "</td>";
+					$html .= "<td>".date($custom_date_format, $timestamp). date(' H:i',strtotime($row->COL_TIME_ON ?? '1970-01-01 00:00:00')) . "</td>";
 					$html .= "<td><a id='edit_qso' href='javascript:displayQso(" . $row->COL_PRIMARY_KEY . ");'>" . str_replace('0','&Oslash;',strtoupper($row->COL_CALL)) . "</a></td>";
 					$html .= $this->part_table_col($row, $this->session->userdata('user_column1')==""?'Mode':$this->session->userdata('user_column1'));
 					$html .= $this->part_table_col($row, $this->session->userdata('user_column2')==""?'RSTS':$this->session->userdata('user_column2'));