diff --git a/oauth2_http/java/com/google/auth/oauth2/ImpersonatedCredentials.java b/oauth2_http/java/com/google/auth/oauth2/ImpersonatedCredentials.java
index 9a86babc9..375d957a4 100644
--- a/oauth2_http/java/com/google/auth/oauth2/ImpersonatedCredentials.java
+++ b/oauth2_http/java/com/google/auth/oauth2/ImpersonatedCredentials.java
@@ -111,7 +111,7 @@ public class ImpersonatedCredentials extends GoogleCredentials
 
   private transient HttpTransportFactory transportFactory;
 
-  @VisibleForTesting transient Calendar calendar = Calendar.getInstance();
+  private transient Calendar calendar;
 
   /**
    * @param sourceCredentials the source credential used to acquire the impersonated credentials. It
@@ -432,6 +432,25 @@ public GoogleCredentials createScoped(Collection<String> scopes) {
         .build();
   }
 
+  /**
+   * Clones the impersonated credentials with a new calendar.
+   *
+   * @param calendar the calendar that will be used by the new ImpersonatedCredentials instance when
+   *     parsing the received expiration time of the refreshed access token
+   * @return the cloned impersonated credentials with the given custom calendar
+   */
+  public ImpersonatedCredentials createWithCustomCalendar(Calendar calendar) {
+    return toBuilder()
+        .setScopes(this.scopes)
+        .setLifetime(this.lifetime)
+        .setDelegates(this.delegates)
+        .setHttpTransportFactory(this.transportFactory)
+        .setQuotaProjectId(this.quotaProjectId)
+        .setIamEndpointOverride(this.iamEndpointOverride)
+        .setCalendar(calendar)
+        .build();
+  }
+
   @Override
   protected Map<String, List<String>> getAdditionalHeaders() {
     Map<String, List<String>> headers = super.getAdditionalHeaders();
@@ -454,6 +473,7 @@ private ImpersonatedCredentials(Builder builder) {
     this.quotaProjectId = builder.quotaProjectId;
     this.iamEndpointOverride = builder.iamEndpointOverride;
     this.transportFactoryClassName = this.transportFactory.getClass().getName();
+    this.calendar = builder.getCalendar();
     if (this.delegates == null) {
       this.delegates = new ArrayList<String>();
     }
@@ -610,6 +630,7 @@ public static class Builder extends GoogleCredentials.Builder {
     private HttpTransportFactory transportFactory;
     private String quotaProjectId;
     private String iamEndpointOverride;
+    private Calendar calendar = Calendar.getInstance();
 
     protected Builder() {}
 
@@ -682,6 +703,15 @@ public Builder setIamEndpointOverride(String iamEndpointOverride) {
       return this;
     }
 
+    public Builder setCalendar(Calendar calendar) {
+      this.calendar = calendar;
+      return this;
+    }
+
+    public Calendar getCalendar() {
+      return this.calendar;
+    }
+
     public ImpersonatedCredentials build() {
       return new ImpersonatedCredentials(this);
     }
diff --git a/oauth2_http/javatests/com/google/auth/oauth2/ImpersonatedCredentialsTest.java b/oauth2_http/javatests/com/google/auth/oauth2/ImpersonatedCredentialsTest.java
index a02158873..4cbacb12d 100644
--- a/oauth2_http/javatests/com/google/auth/oauth2/ImpersonatedCredentialsTest.java
+++ b/oauth2_http/javatests/com/google/auth/oauth2/ImpersonatedCredentialsTest.java
@@ -567,7 +567,6 @@ void refreshAccessToken_delegates_success() throws IOException, IllegalStateExce
 
   @Test
   void refreshAccessToken_GMT_dateParsedCorrectly() throws IOException, IllegalStateException {
-
     Calendar c = Calendar.getInstance();
     c.add(Calendar.SECOND, VALID_LIFETIME);
 
@@ -576,14 +575,15 @@ void refreshAccessToken_GMT_dateParsedCorrectly() throws IOException, IllegalSta
     mockTransportFactory.transport.setExpireTime(getFormattedTime(c.getTime()));
     ImpersonatedCredentials targetCredentials =
         ImpersonatedCredentials.create(
-            sourceCredentials,
-            IMPERSONATED_CLIENT_EMAIL,
-            null,
-            IMMUTABLE_SCOPES_LIST,
-            VALID_LIFETIME,
-            mockTransportFactory);
-    // Set system timezone to GMT
-    targetCredentials.calendar = Calendar.getInstance(TimeZone.getTimeZone("GMT"));
+                sourceCredentials,
+                IMPERSONATED_CLIENT_EMAIL,
+                null,
+                IMMUTABLE_SCOPES_LIST,
+                VALID_LIFETIME,
+                mockTransportFactory)
+            .createWithCustomCalendar(
+                // Set system timezone to GMT
+                Calendar.getInstance(TimeZone.getTimeZone("GMT")));
 
     assertEquals(
         c.getTime().toInstant().truncatedTo(ChronoUnit.SECONDS).toEpochMilli(),
@@ -592,7 +592,6 @@ void refreshAccessToken_GMT_dateParsedCorrectly() throws IOException, IllegalSta
 
   @Test
   void refreshAccessToken_nonGMT_dateParsedCorrectly() throws IOException, IllegalStateException {
-
     Calendar c = Calendar.getInstance();
     c.add(Calendar.SECOND, VALID_LIFETIME);
 
@@ -601,14 +600,15 @@ void refreshAccessToken_nonGMT_dateParsedCorrectly() throws IOException, Illegal
     mockTransportFactory.transport.setExpireTime(getFormattedTime(c.getTime()));
     ImpersonatedCredentials targetCredentials =
         ImpersonatedCredentials.create(
-            sourceCredentials,
-            IMPERSONATED_CLIENT_EMAIL,
-            null,
-            IMMUTABLE_SCOPES_LIST,
-            VALID_LIFETIME,
-            mockTransportFactory);
-    // Set system timezone to one different than GMT
-    targetCredentials.calendar = Calendar.getInstance(TimeZone.getTimeZone("America/Los_Angeles"));
+                sourceCredentials,
+                IMPERSONATED_CLIENT_EMAIL,
+                null,
+                IMMUTABLE_SCOPES_LIST,
+                VALID_LIFETIME,
+                mockTransportFactory)
+            .createWithCustomCalendar(
+                // Set system timezone to one different than GMT
+                Calendar.getInstance(TimeZone.getTimeZone("America/Los_Angeles")));
 
     assertEquals(
         c.getTime().toInstant().truncatedTo(ChronoUnit.SECONDS).toEpochMilli(),