Fix time format validation

src/main/java/com/networknt/schema/format/TimeFormat.java

@@ -57,29 +57,46 @@ public boolean matches(ExecutionContext executionContext, String value) {
             long offset = accessor.getLong(OFFSET_SECONDS) / 60;
             if (MAX_OFFSET_MIN < offset || MIN_OFFSET_MIN > offset) return false;
 
-            long hr = accessor.getLong(HOUR_OF_DAY) - offset / 60;
-            long min = accessor.getLong(MINUTE_OF_HOUR) - offset % 60;
+            long hr = accessor.getLong(HOUR_OF_DAY);
+            long min = accessor.getLong(MINUTE_OF_HOUR);
             long sec = accessor.getLong(SECOND_OF_MINUTE);
 
+            boolean isStandardTimeRange = (sec <= 59 && min <= 59 && hr <= 23);
+            if (isStandardTimeRange) {
+                return true;
+            }
+            // Leap second check normalize to UTC to check if 23:59:60Z
+            hr = hr - offset / 60;
+            min = min - offset % 60;
+
             if (min < 0) {
                 --hr;
                 min += 60;
             }
             if (hr < 0) {
                 hr += 24;
             }
-
-            boolean isStandardTimeRange = (sec <= 59 && min <= 59 && hr <= 23);
-            boolean isSpecialCaseEndOfDay = (sec == 60 && min == 59 && hr == 23);
-
-            return isStandardTimeRange
-                    || isSpecialCaseEndOfDay;
+            return isSpecialCaseLeapSecond(sec, min, hr);
 
         } catch (DateTimeException e) {
             return false;
         }
     }
 
+    /**
+     * Determines if it is a valid leap second.
+     *
+     * See https://datatracker.ietf.org/doc/html/rfc3339#appendix-D
+     *
+     * @param sec second
+     * @param min minute
+     * @param hr  hour
+     * @return true if it is a valid leap second
+     */
+    private boolean isSpecialCaseLeapSecond(long sec, long min, long hr) {
+        return (sec == 60 && min == 59 && hr == 23);
+    }
+
     @Override
     public String getName() {
         return "time";

src/test/java/com/networknt/schema/format/TimeFormatTest.java

@@ -0,0 +1,96 @@
+/*
+ * Copyright (c) 2025 the original author or authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package com.networknt.schema.format;
+
+import static org.junit.jupiter.api.Assertions.assertFalse;
+import static org.junit.jupiter.api.Assertions.assertTrue;
+
+import java.util.Set;
+
+import org.junit.jupiter.params.ParameterizedTest;
+import org.junit.jupiter.params.provider.EnumSource;
+import com.networknt.schema.InputFormat;
+import com.networknt.schema.JsonSchema;
+import com.networknt.schema.JsonSchemaFactory;
+import com.networknt.schema.SchemaValidatorsConfig;
+import com.networknt.schema.SpecVersion.VersionFlag;
+import com.networknt.schema.ValidationMessage;
+
+class TimeFormatTest {
+
+    enum ValidTimeFormatInput {
+        Z_OFFSET_LEAP_SECOND("23:59:60Z"),
+        POSITIVE_OFFSET_LEAP_SECOND("07:59:60+08:00"),
+        NEGATIVE_OFFSET_LEAP_SECOND("15:59:60-08:00"),
+        Z_OFFSET_MIN_TIME("00:00:00Z"),
+        Z_OFFSET("23:59:59Z"),
+        POSITIVE_OFFSET_ZERO("17:00:00+00:00"),
+        POSITIVE_OFFSET_MAX("17:00:00+23:59"),
+        NEGATIVE_OFFSET_ZERO("17:00:00-00:00"),
+        NEGATIVE_OFFSET_ONE_DAY("17:00:00-07:00"),
+        NEGATIVE_OFFSET_MAX("17:00:00-23:59");
+
+        String format;
+
+        ValidTimeFormatInput(String format) {
+            this.format = format;
+        }
+    }
+
+    @ParameterizedTest
+    @EnumSource(ValidTimeFormatInput.class)
+    void validTimeShouldPass(ValidTimeFormatInput input) {
+        String schemaData = "{\r\n"
+                + "  \"format\": \"time\"\r\n"
+                + "}";
+
+        String inputData = "\""+input.format+"\"";
+
+        SchemaValidatorsConfig config = SchemaValidatorsConfig.builder().formatAssertionsEnabled(true).build();
+        JsonSchema schema = JsonSchemaFactory.getInstance(VersionFlag.V202012).getSchema(schemaData, config);
+        Set<ValidationMessage> messages = schema.validate(inputData, InputFormat.JSON);
+        assertTrue(messages.isEmpty());
+    }
+
+    enum InvalidTimeFormatInput {
+        NEGATIVE_OFFSET_INVALID_LEAP_SECOND("23:59:60-07:00"),
+        Z_OFFSET_EXCEED_LEAP_SECOND("23:59:61Z"),
+        Z_OFFSET_EXCEED_TIME("24:00:00Z"),
+        POSITIVE_OFFSET_EXCEED_MAX("17:00:00+24:00"),
+        NEGATIVE_OFFSET_EXCEED_MAX("17:00:00-24:00");
+
+        String format;
+
+        InvalidTimeFormatInput(String format) {
+            this.format = format;
+        }
+    }
+
+    @ParameterizedTest
+    @EnumSource(InvalidTimeFormatInput.class)
+    void invalidTimeShouldFail(InvalidTimeFormatInput input) {
+        String schemaData = "{\r\n"
+                + "  \"format\": \"time\"\r\n"
+                + "}";
+
+        String inputData = "\""+input.format+"\"";
+
+        SchemaValidatorsConfig config = SchemaValidatorsConfig.builder().formatAssertionsEnabled(true).build();
+        JsonSchema schema = JsonSchemaFactory.getInstance(VersionFlag.V202012).getSchema(schemaData, config);
+        Set<ValidationMessage> messages = schema.validate(inputData, InputFormat.JSON);
+        assertFalse(messages.isEmpty());
+    }
+}