diff --git a/include/valijson/validation_visitor.hpp b/include/valijson/validation_visitor.hpp
index 3adb0d1..152d101 100644
--- a/include/valijson/validation_visitor.hpp
+++ b/include/valijson/validation_visitor.hpp
@@ -375,7 +375,7 @@ public:
             }
         } else if (format == "time") {
             // Matches times like: 16:52:45Z, 16:52:45+02:00
-            std::regex time_regex("^([01][0-9]|2[0-3]):([0-5][0-9]):([0-5][0-9]|60)(\.[0-9]+)?(([Zz])|([\+|\-]([01][0-9]|2[0-3]):[0-5][0-9]))$");
+            std::regex time_regex("^([01][0-9]|2[0-3]):([0-5][0-9]):([0-5][0-9]|60)(\\.[0-9]+)?(([Zz])|([\\+|\\-]([01][0-9]|2[0-3]):[0-5][0-9]))$");
             if (std::regex_match(s, time_regex)) {
                 return true;
             } else {
@@ -387,7 +387,7 @@ public:
             }
         } else if (format == "date-time") {
             // Matches data times like: 2022-07-18T16:52:45Z, 2022-07-18T16:52:45+02:00
-            std::regex datetime_regex("^([0-9]+)-(0[1-9]|1[012])-(0[1-9]|[12][0-9]|3[01])[Tt]([01][0-9]|2[0-3]):([0-5][0-9]):([0-5][0-9]|60)(\.[0-9]+)?(([Zz])|([\+|\-]([01][0-9]|2[0-3]):[0-5][0-9]))$");
+            std::regex datetime_regex("^([0-9]+)-(0[1-9]|1[012])-(0[1-9]|[12][0-9]|3[01])[Tt]([01][0-9]|2[0-3]):([0-5][0-9]):([0-5][0-9]|60)(\\.[0-9]+)?(([Zz])|([\\+|\\-]([01][0-9]|2[0-3]):[0-5][0-9]))$");
             std::smatch matches;
             if (std::regex_match(s, matches, datetime_regex)) {
                 const auto month = std::stoi(matches[2].str());