diff --git a/pom.xml b/pom.xml
index 49214b9c..9192d76a 100644
--- a/pom.xml
+++ b/pom.xml
@@ -38,7 +38,7 @@
 
     <properties>
         <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
-        <vertxVersion>4.5.4</vertxVersion>
+        <vertxVersion>4.5.7</vertxVersion>
         <commonmarkVersion>0.21.0</commonmarkVersion>
         <jacksonVersion>2.15.3</jacksonVersion>
         <poiVersion>5.2.5</poiVersion>
@@ -145,6 +145,11 @@
             <artifactId>vertx-redis-client</artifactId>
             <version>${vertxVersion}</version>
         </dependency>
+        <dependency>
+            <groupId>io.vertx</groupId>
+            <artifactId>vertx-json-schema</artifactId>
+            <version>${vertxVersion}</version>
+        </dependency>
         <dependency>
             <groupId>org.apache.poi</groupId>
             <artifactId>poi</artifactId>
diff --git a/src/main/java/io/github/sinri/keel/core/KeelCronExpression.java b/src/main/java/io/github/sinri/keel/core/KeelCronExpression.java
index a866978c..b29cd582 100644
--- a/src/main/java/io/github/sinri/keel/core/KeelCronExpression.java
+++ b/src/main/java/io/github/sinri/keel/core/KeelCronExpression.java
@@ -104,6 +104,13 @@ private void parseField(@Nonnull String rawComponent, @Nonnull Set<Integer> opti
         }
     }
 
+    /**
+     * @since 3.2.4
+     */
+    public static ParsedCalenderElements parseCalenderToElements(@Nonnull Calendar currentCalendar) {
+        return new ParsedCalenderElements(currentCalendar);
+    }
+
     @Nonnull
     public String getRawCronExpression() {
         return rawCronExpression;
@@ -119,17 +126,21 @@ public static class ParsedCalenderElements {
         public final int month;
         public final int weekday;
 
+        // debug use
+        public final int second;
+
         public ParsedCalenderElements(@Nonnull Calendar currentCalendar) {
             minute = currentCalendar.get(Calendar.MINUTE);
             hour = currentCalendar.get(Calendar.HOUR_OF_DAY);
             day = currentCalendar.get(Calendar.DAY_OF_MONTH);
             month = 1 + currentCalendar.get(Calendar.MONTH);// make JAN 1, ...
             weekday = currentCalendar.get(Calendar.DAY_OF_WEEK) - 1; // make sunday 0, ...
+            second = currentCalendar.get(Calendar.SECOND);
         }
 
         @Override
         public String toString() {
-            return minute + " " + hour + " " + day + " " + month + " " + weekday;
+            return "(" + second + ") " + minute + " " + hour + " " + day + " " + month + " " + weekday;
         }
     }
 
diff --git a/src/main/java/io/github/sinri/keel/core/json/scheme/JsonArrayScheme.java b/src/main/java/io/github/sinri/keel/core/json/scheme/JsonArrayScheme.java
index 35834fa4..1e5b5d7d 100644
--- a/src/main/java/io/github/sinri/keel/core/json/scheme/JsonArrayScheme.java
+++ b/src/main/java/io/github/sinri/keel/core/json/scheme/JsonArrayScheme.java
@@ -10,6 +10,7 @@
 /**
  * @since 2.7
  */
+@Deprecated(since = "3.2.4")
 public class JsonArrayScheme extends JsonValueScheme<JsonArray> {
     private final Map<Integer, JsonElementScheme<?>> indexedElementSchemeMap = new LinkedHashMap<>();
     private JsonElementScheme<?> defaultElementScheme;
diff --git a/src/main/java/io/github/sinri/keel/core/json/scheme/JsonBooleanScheme.java b/src/main/java/io/github/sinri/keel/core/json/scheme/JsonBooleanScheme.java
index fd19fc7a..87c90b2d 100644
--- a/src/main/java/io/github/sinri/keel/core/json/scheme/JsonBooleanScheme.java
+++ b/src/main/java/io/github/sinri/keel/core/json/scheme/JsonBooleanScheme.java
@@ -7,6 +7,7 @@
 /**
  * @since 2.7
  */
+@Deprecated(since = "3.2.4")
 public class JsonBooleanScheme extends JsonValueScheme<Boolean> {
     private Boolean expected;
 
diff --git a/src/main/java/io/github/sinri/keel/core/json/scheme/JsonElementScheme.java b/src/main/java/io/github/sinri/keel/core/json/scheme/JsonElementScheme.java
index 51d0f274..206873c8 100644
--- a/src/main/java/io/github/sinri/keel/core/json/scheme/JsonElementScheme.java
+++ b/src/main/java/io/github/sinri/keel/core/json/scheme/JsonElementScheme.java
@@ -6,6 +6,7 @@
 /**
  * @since 2.7
  */
+@Deprecated(since = "3.2.4")
 public interface JsonElementScheme<T> extends JsonifiableEntity<JsonElementScheme<T>> {
     static JsonElementScheme<?> fromJsonObject(JsonObject jsonObject) {
         JsonElementSchemeType scheme_type = JsonElementSchemeType.valueOf(jsonObject.getString("scheme_type"));
diff --git a/src/main/java/io/github/sinri/keel/core/json/scheme/JsonNullScheme.java b/src/main/java/io/github/sinri/keel/core/json/scheme/JsonNullScheme.java
index bc5f0ceb..66a7c1a4 100644
--- a/src/main/java/io/github/sinri/keel/core/json/scheme/JsonNullScheme.java
+++ b/src/main/java/io/github/sinri/keel/core/json/scheme/JsonNullScheme.java
@@ -7,6 +7,7 @@
 /**
  * @since 2.7
  */
+@Deprecated(since = "3.2.4")
 public class JsonNullScheme extends JsonValueScheme<Object> {
     public JsonNullScheme() {
         super();
diff --git a/src/main/java/io/github/sinri/keel/core/json/scheme/JsonNumberScheme.java b/src/main/java/io/github/sinri/keel/core/json/scheme/JsonNumberScheme.java
index 03fd98df..5ea412f7 100644
--- a/src/main/java/io/github/sinri/keel/core/json/scheme/JsonNumberScheme.java
+++ b/src/main/java/io/github/sinri/keel/core/json/scheme/JsonNumberScheme.java
@@ -8,6 +8,7 @@
 /**
  * @since 2.7
  */
+@Deprecated(since = "3.2.4")
 public class JsonNumberScheme extends JsonValueScheme<Number> {
     //private boolean withFractions;
 
diff --git a/src/main/java/io/github/sinri/keel/core/json/scheme/JsonObjectScheme.java b/src/main/java/io/github/sinri/keel/core/json/scheme/JsonObjectScheme.java
index 64726140..f15e870b 100644
--- a/src/main/java/io/github/sinri/keel/core/json/scheme/JsonObjectScheme.java
+++ b/src/main/java/io/github/sinri/keel/core/json/scheme/JsonObjectScheme.java
@@ -9,6 +9,7 @@
 /**
  * @since 2.7
  */
+@Deprecated(since = "3.2.4")
 public class JsonObjectScheme extends JsonValueScheme<JsonObject> {
 
     private final Map<String, JsonElementScheme<?>> elementSchemeMap = new LinkedHashMap<>();
diff --git a/src/main/java/io/github/sinri/keel/core/json/scheme/JsonPlainScheme.java b/src/main/java/io/github/sinri/keel/core/json/scheme/JsonPlainScheme.java
index 520b636e..aafe81c1 100644
--- a/src/main/java/io/github/sinri/keel/core/json/scheme/JsonPlainScheme.java
+++ b/src/main/java/io/github/sinri/keel/core/json/scheme/JsonPlainScheme.java
@@ -4,6 +4,7 @@
 
 import javax.annotation.Nonnull;
 
+@Deprecated(since = "3.2.4")
 public class JsonPlainScheme extends JsonValueScheme<Object> {
 
     @Override
diff --git a/src/main/java/io/github/sinri/keel/core/json/scheme/JsonSchemeMismatchException.java b/src/main/java/io/github/sinri/keel/core/json/scheme/JsonSchemeMismatchException.java
index c9b9e463..58f6dead 100644
--- a/src/main/java/io/github/sinri/keel/core/json/scheme/JsonSchemeMismatchException.java
+++ b/src/main/java/io/github/sinri/keel/core/json/scheme/JsonSchemeMismatchException.java
@@ -6,6 +6,7 @@
 
 import static io.github.sinri.keel.helper.KeelHelpersInterface.KeelHelpers;
 
+@Deprecated(since = "3.2.4")
 public class JsonSchemeMismatchException extends Exception {
     public static final String RuleSchemeError = "SchemeError";
     public static final String RuleEmptyArrayNotAllowed = "EmptyArrayNotAllowed";
diff --git a/src/main/java/io/github/sinri/keel/core/json/scheme/JsonStringScheme.java b/src/main/java/io/github/sinri/keel/core/json/scheme/JsonStringScheme.java
index a426b0ef..70a847db 100644
--- a/src/main/java/io/github/sinri/keel/core/json/scheme/JsonStringScheme.java
+++ b/src/main/java/io/github/sinri/keel/core/json/scheme/JsonStringScheme.java
@@ -8,6 +8,7 @@
 /**
  * @since 2.7
  */
+@Deprecated(since = "3.2.4")
 public class JsonStringScheme extends JsonValueScheme<String> {
 
     private Pattern pattern;
diff --git a/src/main/java/io/github/sinri/keel/core/json/scheme/JsonValueScheme.java b/src/main/java/io/github/sinri/keel/core/json/scheme/JsonValueScheme.java
index 1e4c402b..3ac056ac 100644
--- a/src/main/java/io/github/sinri/keel/core/json/scheme/JsonValueScheme.java
+++ b/src/main/java/io/github/sinri/keel/core/json/scheme/JsonValueScheme.java
@@ -7,6 +7,7 @@
 /**
  * @since 2.7
  */
+@Deprecated(since = "3.2.4")
 abstract public class JsonValueScheme<T> implements JsonElementScheme<T> {
 
     protected T digested;
diff --git a/src/main/java/io/github/sinri/keel/servant/sundial/KeelSundial.java b/src/main/java/io/github/sinri/keel/servant/sundial/KeelSundial.java
index 592fc65f..1a2583a3 100644
--- a/src/main/java/io/github/sinri/keel/servant/sundial/KeelSundial.java
+++ b/src/main/java/io/github/sinri/keel/servant/sundial/KeelSundial.java
@@ -32,10 +32,9 @@ protected KeelEventLogger buildEventLogger() {
     @Override
 
     public void start() throws Exception {
-        long delaySeconds = 60 - (System.currentTimeMillis() / 1000) % 60;
-        this.timerID = Keel.getVertx().setPeriodic(delaySeconds, 60_000L, timerID -> {
-            Calendar calendar = Calendar.getInstance();
-            handleEveryMinute(calendar);
+        int delaySeconds = 61 - KeelCronExpression.parseCalenderToElements(Calendar.getInstance()).second;
+        this.timerID = Keel.getVertx().setPeriodic(delaySeconds * 1000L, 60_000L, timerID -> {
+            handleEveryMinute(Calendar.getInstance());
             refreshPlans();
         });
     }