diff --git a/application/controllers/Logbook.php b/application/controllers/Logbook.php
index a4f6766e4..56d75669c 100644
--- a/application/controllers/Logbook.php
+++ b/application/controllers/Logbook.php
@@ -77,10 +77,14 @@ class Logbook extends CI_Controller {
 
 		// Normalize the date only if it's not empty
 		if (!empty($date)) {
+			// Characters '/' and ',' are not URL safe, so we replace
+			// them with  '_' and '%'. Switch them back here.
 			if (strpos($date, '_') !== false) {
-				// Replace slashes with dashes for URL processing
 				$date = str_replace('_', '/', $date);
 			}
+			if (strpos($date, '%') !== false) {
+				$date = str_replace('%', ',', $date);
+			}
 			// Get user-preferred date format
 			if ($this->session->userdata('user_date_format')) {
 				$date_format = $this->session->userdata('user_date_format');
diff --git a/assets/js/sections/qso.js b/assets/js/sections/qso.js
index c363a4e92..8772953b4 100644
--- a/assets/js/sections/qso.js
+++ b/assets/js/sections/qso.js
@@ -911,9 +911,14 @@ $("#callsign").on("focusout", function () {
 		let find_callsign = $(this).val().toUpperCase();
 		let callsign = find_callsign;
 		let startDate = $('#start_date').val();
+		// Characters '/' and ',' are not URL safe, so we replace
+		// them with  '_' and '%'.
 		if (startDate.includes('/')) {
 			startDate = startDate.replaceAll('/', '_');
 		}
+		if (startDate.includes(',')) {
+			startDate = startDate.replaceAll(',', '%');
+		}
 		startDate = encodeURIComponent(startDate);
 		const stationProfile = $('#stationProfile').val();