microsoft · yury-s · Jun 19, 2026
diff --git a/playwright/src/main/java/com/microsoft/playwright/Clock.java b/playwright/src/main/java/com/microsoft/playwright/Clock.java
@@ -17,6 +17,7 @@
 package com.microsoft.playwright;
 
 import java.util.Date;
+import java.time.Instant;
 
 /**
  * Accurately simulating time-dependent behavior is essential for verifying the correctness of applications. Learn more
@@ -53,6 +54,13 @@ public InstallOptions setTime(Date time) {
       this.time = time;
       return this;
     }
+    /**
+     * Time to initialize with, current system time by default.
+     */
+    public InstallOptions setTime(Instant time) {
+      this.time = time;
+      return this;
+    }
   }
   /**
    * Advance the clock by jumping forward in time. Only fires due timers at most once. This is equivalent to user closing the
@@ -257,6 +265,39 @@ default void install() {
    * @since v1.45
    */
   void pauseAt(Date time);
+  /**
+   * Advance the clock by jumping forward in time and pause the time. Once this method is called, no timers are fired unless
+   * {@link com.microsoft.playwright.Clock#runFor Clock.runFor()}, {@link com.microsoft.playwright.Clock#fastForward
+   * Clock.fastForward()}, {@link com.microsoft.playwright.Clock#pauseAt Clock.pauseAt()} or {@link
+   * com.microsoft.playwright.Clock#resume Clock.resume()} is called.
+   *
+   * <p> Only fires due timers at most once. This is equivalent to user closing the laptop lid for a while and reopening it at
+   * the specified time and pausing.
+   *
+   * <p> <strong>Usage</strong>
+   * <pre>{@code
+   * SimpleDateFormat format = new SimpleDateFormat("yyy-MM-dd");
+   * page.clock().pauseAt(format.parse("2020-02-02"));
+   * page.clock().pauseAt("2020-02-02");
+   * }</pre>
+   *
+   * <p> For best results, install the clock before navigating the page and set it to a time slightly before the intended test
+   * time. This ensures that all timers run normally during page loading, preventing the page from getting stuck. Once the
+   * page has fully loaded, you can safely use {@link com.microsoft.playwright.Clock#pauseAt Clock.pauseAt()} to pause the
+   * clock.
+   * <pre>{@code
+   * // Initialize clock with some time before the test time and let the page load
+   * // naturally. `Date.now` will progress as the timers fire.
+   * SimpleDateFormat format = new SimpleDateFormat("yyy-MM-dd'T'HH:mm:ss");
+   * page.clock().install(new Clock.InstallOptions().setTime(format.parse("2024-12-10T08:00:00")));
+   * page.navigate("http://localhost:3333");
+   * page.clock().pauseAt(format.parse("2024-12-10T10:00:00"));
+   * }</pre>
+   *
+   * @param time Time to pause at.
+   * @since v1.45
+   */
+  void pauseAt(Instant time);
   /**
    * Resumes timers. Once this method is called, time resumes flowing, timers are fired as usual.
    *
@@ -317,6 +358,24 @@ default void install() {
    * @since v1.45
    */
   void setFixedTime(Date time);
+  /**
+   * Makes {@code Date.now} and {@code new Date()} return fixed fake time at all times, keeps all the timers running.
+   *
+   * <p> Use this method for simple scenarios where you only need to test with a predefined time. For more advanced scenarios,
+   * use {@link com.microsoft.playwright.Clock#install Clock.install()} instead. Read docs on <a
+   * href="https://playwright.dev/java/docs/clock">clock emulation</a> to learn more.
+   *
+   * <p> <strong>Usage</strong>
+   * <pre>{@code
+   * page.clock().setFixedTime(new Date());
+   * page.clock().setFixedTime(new SimpleDateFormat("yyy-MM-dd").parse("2020-02-02"));
+   * page.clock().setFixedTime("2020-02-02");
+   * }</pre>
+   *
+   * @param time Time to be set in milliseconds.
+   * @since v1.45
+   */
+  void setFixedTime(Instant time);
   /**
    * Sets system time, but does not trigger any timers. Use this to test how the web page reacts to a time shift, for example
    * switching from summer to winter time, or changing time zones.
@@ -362,5 +421,20 @@ default void install() {
    * @since v1.45
    */
   void setSystemTime(Date time);
+  /**
+   * Sets system time, but does not trigger any timers. Use this to test how the web page reacts to a time shift, for example
+   * switching from summer to winter time, or changing time zones.
+   *
+   * <p> <strong>Usage</strong>
+   * <pre>{@code
+   * page.clock().setSystemTime(new Date());
+   * page.clock().setSystemTime(new SimpleDateFormat("yyy-MM-dd").parse("2020-02-02"));
+   * page.clock().setSystemTime("2020-02-02");
+   * }</pre>
+   *
+   * @param time Time to be set in milliseconds.
+   * @since v1.45
+   */
+  void setSystemTime(Instant time);
 }
 
diff --git a/playwright/src/main/java/com/microsoft/playwright/impl/ClockImpl.java b/playwright/src/main/java/com/microsoft/playwright/impl/ClockImpl.java
@@ -3,6 +3,7 @@
 import com.google.gson.JsonObject;
 import com.microsoft.playwright.Clock;
 
+import java.time.Instant;
 import java.util.Date;
 
 import static com.microsoft.playwright.impl.ChannelOwner.NO_TIMEOUT;
@@ -72,9 +73,12 @@ public void pauseAt(String time) {
 
   @Override
   public void pauseAt(Date time) {
-    JsonObject params = new JsonObject();
-    params.addProperty("timeNumber", time.getTime());
-    sendMessageWithLogging("pauseAt", params);
+    pauseAt(time.getTime());
+  }
+
+  @Override
+  public void pauseAt(Instant time) {
+    pauseAt(time.toEpochMilli());
   }
 
   @Override
@@ -98,9 +102,12 @@ public void setFixedTime(String time) {
 
   @Override
   public void setFixedTime(Date time) {
-    JsonObject params = new JsonObject();
-    params.addProperty("timeNumber", time.getTime());
-    sendMessageWithLogging("setFixedTime", params);
+    setFixedTime(time.getTime());
+  }
+
+  @Override
+  public void setFixedTime(Instant time) {
+    setFixedTime(time.toEpochMilli());
   }
 
   @Override
@@ -119,16 +126,21 @@ public void setSystemTime(String time) {
 
   @Override
   public void setSystemTime(Date time) {
-    JsonObject params = new JsonObject();
-    params.addProperty("timeNumber", time.getTime());
-    sendMessageWithLogging("setSystemTime", params);
+    setSystemTime(time.getTime());
+  }
+
+  @Override
+  public void setSystemTime(Instant time) {
+    setSystemTime(time.toEpochMilli());
   }
 
   private static void parseTime(Object time, JsonObject params) {
     if (time instanceof Long) {
       params.addProperty("timeNumber", (Long) time);
     } else if (time instanceof Date) {
       params.addProperty("timeNumber", ((Date) time).getTime());
+    } else if (time instanceof Instant) {
+      params.addProperty("timeNumber", ((Instant) time).toEpochMilli());
     } else if (time instanceof String) {
       params.addProperty("timeString", (String) time);
     }

diff --git a/playwright/src/test/java/com/microsoft/playwright/TestPageClock.java b/playwright/src/test/java/com/microsoft/playwright/TestPageClock.java
@@ -9,6 +9,9 @@
 import java.io.Writer;
 import java.text.ParseException;
 import java.text.SimpleDateFormat;
+import java.time.Instant;
+import java.time.LocalDateTime;
+import java.time.ZoneOffset;
 import java.util.ArrayList;
 import java.util.Date;
 
@@ -350,6 +353,25 @@ void setFixedTimeAllowsInstallingFakeTimersAfterSettingTime(Page page) {
     assertEquals(200, ((Object[]) calls.get(0))[0]);
   }
 
+  @Test
+  void acceptsInstant(Page page) {
+    // A LocalDateTime has no time zone, so convert it to an Instant at an explicit offset.
+    page.clock().install(new Clock.InstallOptions().setTime(
+      LocalDateTime.of(2024, 12, 10, 8, 0, 0).toInstant(ZoneOffset.UTC)));
+
+    Instant paused = LocalDateTime.of(2024, 12, 10, 10, 0, 0).toInstant(ZoneOffset.UTC);
+    page.clock().pauseAt(paused);
+    assertEquals(paused.toEpochMilli(), ((Number) page.evaluate("() => Date.now()")).longValue());
+
+    Instant system = LocalDateTime.of(2024, 12, 10, 12, 0, 0).toInstant(ZoneOffset.UTC);
+    page.clock().setSystemTime(system);
+    assertEquals(system.toEpochMilli(), ((Number) page.evaluate("() => Date.now()")).longValue());
+
+    Instant fixed = LocalDateTime.of(2024, 12, 10, 14, 0, 0).toInstant(ZoneOffset.UTC);
+    page.clock().setFixedTime(fixed);
+    assertEquals(fixed.toEpochMilli(), ((Number) page.evaluate("() => Date.now()")).longValue());
+  }
+
   @Test
   void whileRunningShouldProgressTime(Page page) {
     page.clock().install(new Clock.InstallOptions().setTime(0));

diff --git a/tools/api-generator/src/main/java/com/microsoft/playwright/tools/ApiGenerator.java b/tools/api-generator/src/main/java/com/microsoft/playwright/tools/ApiGenerator.java
@@ -402,13 +402,23 @@ private List<JsonObject> supportedUnionTypes() {
     return result;
   }
 
+  // The Clock time parameters are a union of number|string|Date. java.util.Date is a legacy type,
+  // so for Date-typed unions we additionally generate a java.time.Instant overload.
+  private static boolean hasDate(List<JsonObject> unionTypes) {
+    return unionTypes.stream().anyMatch(o -> "Date".equals(o.get("name").getAsString()));
+  }
+
   int unionSize() {
-    return supportedUnionTypes().size();
+    List<JsonObject> types = supportedUnionTypes();
+    return types.size() + (hasDate(types) ? 1 : 0);
   }
 
   String formatTypeFromUnion(int i) {
-    JsonElement overloadedType = supportedUnionTypes().get(i);
-    return convertBuiltinType(overloadedType.getAsJsonObject());
+    List<JsonObject> types = supportedUnionTypes();
+    if (i == types.size() && hasDate(types)) {
+      return "Instant";
+    }
+    return convertBuiltinType(types.get(i));
   }
 
   boolean isNullable() {
@@ -1012,6 +1022,7 @@ void writeTo(List<String> output, String offset) {
     }
     if ("Clock".equals(jsonName)) {
       output.add("import java.util.Date;");
+      output.add("import java.time.Instant;");
     }
     if (asList("Page", "Frame", "ElementHandle", "Locator", "LocatorAssertions", "APIRequest", "Browser", "BrowserContext", "BrowserType", "Route", "Request", "Response", "JSHandle", "ConsoleMessage", "APIResponse", "Playwright", "Debugger", "Screencast", "WebSocketRoute", "Credentials", "WebStorage").contains(jsonName)) {
       output.add("import java.util.*;");