@@ -21,4 +21,9 @@
 <method>com.google.cloud.storage.BucketInfo$Builder deleteLifecycleRules()</method>
 <differenceType>7013</differenceType>
 </difference>
+<difference>
+<className>com/google/cloud/storage/BucketInfo$Builder</className>
+<method>com.google.cloud.storage.BucketInfo$Builder setUpdateTime(java.lang.Long)</method>
+<differenceType>7013</differenceType>
+</difference>
 </differences>

@@ -601,6 +601,12 @@ Builder setCreateTime(Long createTime) {
 return this;
 }
 
+@Override
+Builder setUpdateTime(Long updateTime) {
+infoBuilder.setUpdateTime(updateTime);
+return this;
+}
+
 @Override
 Builder setMetageneration(Long metageneration) {
 infoBuilder.setMetageneration(metageneration);

@@ -84,6 +84,7 @@ public com.google.api.services.storage.model.Bucket apply(BucketInfo bucketInfo)
 private final List<LifecycleRule> lifecycleRules;
 private final String etag;
 private final Long createTime;
+private final Long updateTime;
 private final Long metageneration;
 private final List<Cors> cors;
 private final List<Acl> acl;
@@ -1005,6 +1006,8 @@ public abstract static class Builder {
 
 abstract Builder setCreateTime(Long createTime);
 
+abstract Builder setUpdateTime(Long updateTime);
+
 abstract Builder setMetageneration(Long metageneration);
 
 abstract Builder setLocationType(String locationType);
@@ -1090,6 +1093,7 @@ static final class BuilderImpl extends Builder {
 private String location;
 private String etag;
 private Long createTime;
+private Long updateTime;
 private Long metageneration;
 private List<Cors> cors;
 private List<Acl> acl;
@@ -1113,6 +1117,7 @@ static final class BuilderImpl extends Builder {
 name = bucketInfo.name;
 etag = bucketInfo.etag;
 createTime = bucketInfo.createTime;
+updateTime = bucketInfo.updateTime;
 metageneration = bucketInfo.metageneration;
 location = bucketInfo.location;
 storageClass = bucketInfo.storageClass;
@@ -1232,6 +1237,12 @@ Builder setCreateTime(Long createTime) {
 return this;
 }
 
+@Override
+Builder setUpdateTime(Long updateTime) {
+this.updateTime = updateTime;
+return this;
+}
+
 @Override
 Builder setMetageneration(Long metageneration) {
 this.metageneration = metageneration;
@@ -1337,6 +1348,7 @@ public BucketInfo build() {
 name = builder.name;
 etag = builder.etag;
 createTime = builder.createTime;
+updateTime = builder.updateTime;
 metageneration = builder.metageneration;
 location = builder.location;
 storageClass = builder.storageClass;
@@ -1468,6 +1480,14 @@ public Long getCreateTime() {
 return createTime;
 }
 
+/**
+* Returns the last modification time of the bucket's metadata expressed as the number of
+* milliseconds since the Unix epoch.
+*/
+public Long getUpdateTime() {
+return updateTime;
+}
+
 /** Returns the metadata generation of this bucket. */
 public Long getMetageneration() {
 return metageneration;
@@ -1650,6 +1670,9 @@ com.google.api.services.storage.model.Bucket toPb() {
 if (createTime != null) {
 bucketPb.setTimeCreated(new DateTime(createTime));
 }
+if (updateTime != null) {
+bucketPb.setUpdated(new DateTime(updateTime));
+}
 if (metageneration != null) {
 bucketPb.setMetageneration(metageneration);
 }
@@ -1797,6 +1820,9 @@ static BucketInfo fromPb(com.google.api.services.storage.model.Bucket bucketPb)
 if (bucketPb.getTimeCreated() != null) {
 builder.setCreateTime(bucketPb.getTimeCreated().getValue());
 }
+if (bucketPb.getUpdated() != null) {
+builder.setUpdateTime(bucketPb.getUpdated().getValue());
+}
 if (bucketPb.getLocation() != null) {
 builder.setLocation(bucketPb.getLocation());
 }

@@ -56,6 +56,7 @@ public class BucketInfoTest {
 private static final User OWNER = new User("[email protected]");
 private static final String SELF_LINK = "http://storage/b/n";
 private static final Long CREATE_TIME = System.currentTimeMillis();
+private static final Long UPDATE_TIME = CREATE_TIME;
 private static final List<Cors> CORS = Collections.singletonList(Cors.newBuilder().build());
 private static final List<Acl> DEFAULT_ACL =
 Collections.singletonList(Acl.of(User.ofAllAuthenticatedUsers(), Role.WRITER));
@@ -117,6 +118,7 @@ public class BucketInfoTest {
 .setSelfLink(SELF_LINK)
 .setCors(CORS)
 .setCreateTime(CREATE_TIME)
+.setUpdateTime(UPDATE_TIME)
 .setDefaultAcl(DEFAULT_ACL)
 .setDeleteRules(DELETE_RULES)
 .setLifecycleRules(LIFECYCLE_RULES)
@@ -148,6 +150,7 @@ public class BucketInfoTest {
 .setSelfLink(SELF_LINK)
 .setCors(CORS)
 .setCreateTime(CREATE_TIME)
+.setUpdateTime(UPDATE_TIME)
 .setDefaultAcl(DEFAULT_ACL)
 .setDeleteRules(DELETE_RULES)
 .setLifecycleRules(LIFECYCLE_RULES)
@@ -202,6 +205,7 @@ public void testBuilder() {
 assertEquals(OWNER, BUCKET_INFO.getOwner());
 assertEquals(SELF_LINK, BUCKET_INFO.getSelfLink());
 assertEquals(CREATE_TIME, BUCKET_INFO.getCreateTime());
+assertEquals(UPDATE_TIME, BUCKET_INFO.getUpdateTime());
 assertEquals(CORS, BUCKET_INFO.getCors());
 assertEquals(DEFAULT_ACL, BUCKET_INFO.getDefaultAcl());
 assertEquals(DELETE_RULES, BUCKET_INFO.getDeleteRules());
@@ -223,6 +227,7 @@ public void testBuilder() {
 }
 
 @Test
+@SuppressWarnings({"unchecked", "deprecation"})
 public void testToPbAndFromPb() {
 compareBuckets(BUCKET_INFO, BucketInfo.fromPb(BUCKET_INFO.toPb()));
 BucketInfo bucketInfo =
@@ -245,6 +250,7 @@ private void compareBuckets(BucketInfo expected, BucketInfo value) {
 assertEquals(expected.getOwner(), value.getOwner());
 assertEquals(expected.getSelfLink(), value.getSelfLink());
 assertEquals(expected.getCreateTime(), value.getCreateTime());
+assertEquals(expected.getUpdateTime(), value.getUpdateTime());
 assertEquals(expected.getCors(), value.getCors());
 assertEquals(expected.getDefaultAcl(), value.getDefaultAcl());
 assertEquals(expected.getDeleteRules(), value.getDeleteRules());

@@ -69,6 +69,7 @@ public class BucketTest {
 private static final User OWNER = new User("[email protected]");
 private static final String SELF_LINK = "http://storage/b/n";
 private static final Long CREATE_TIME = System.currentTimeMillis();
+private static final Long UPDATE_TIME = CREATE_TIME - 1L;
 private static final List<Cors> CORS = Collections.singletonList(Cors.newBuilder().build());
 private static final List<Acl> DEFAULT_ACL =
 Collections.singletonList(Acl.of(User.ofAllAuthenticatedUsers(), WRITER));
@@ -111,6 +112,7 @@ public class BucketTest {
 .setSelfLink(SELF_LINK)
 .setCors(CORS)
 .setCreateTime(CREATE_TIME)
+.setUpdateTime(UPDATE_TIME)
 .setDefaultAcl(DEFAULT_ACL)
 .setDeleteRules(DELETE_RULES)
 .setLifecycleRules(LIFECYCLE_RULES)
@@ -803,6 +805,7 @@ public void testBuilder() {
 .setSelfLink(SELF_LINK)
 .setCors(CORS)
 .setCreateTime(CREATE_TIME)
+.setUpdateTime(UPDATE_TIME)
 .setDefaultAcl(DEFAULT_ACL)
 .setDeleteRules(DELETE_RULES)
 .setLifecycleRules(LIFECYCLE_RULES)
@@ -828,6 +831,7 @@ public void testBuilder() {
 assertEquals(OWNER, bucket.getOwner());
 assertEquals(SELF_LINK, bucket.getSelfLink());
 assertEquals(CREATE_TIME, bucket.getCreateTime());
+assertEquals(UPDATE_TIME, bucket.getUpdateTime());
 assertEquals(CORS, bucket.getCors());
 assertEquals(DEFAULT_ACL, bucket.getDefaultAcl());
 assertEquals(DELETE_RULES, bucket.getDeleteRules());

@@ -3535,4 +3535,26 @@ public void testRemoveBucketCORS() throws ExecutionException, InterruptedExcepti
 RemoteStorageHelper.forceDelete(storage, bucketName, 5, TimeUnit.SECONDS);
 }
 }
+
+@Test
+public void testBucketUpdateTime() throws ExecutionException, InterruptedException {
+String bucketName = RemoteStorageHelper.generateBucketName();
+BucketInfo bucketInfo =
+BucketInfo.newBuilder(bucketName).setLocation("us").setVersioningEnabled(true).build();
+try {
+Bucket bucket = storage.create(bucketInfo);
+assertThat(bucket).isNotNull();
+assertThat(bucket.versioningEnabled()).isTrue();
+assertThat(bucket.getCreateTime()).isNotNull();
+assertThat(bucket.getUpdateTime()).isEqualTo(bucket.getCreateTime());
+
+Bucket updatedBucket = bucket.toBuilder().setVersioningEnabled(false).build().update();
+assertThat(updatedBucket.versioningEnabled()).isFalse();
+assertThat(updatedBucket.getUpdateTime()).isNotNull();
+assertThat(updatedBucket.getCreateTime()).isEqualTo(bucket.getCreateTime());
+assertThat(updatedBucket.getUpdateTime()).isGreaterThan(bucket.getCreateTime());
+} finally {
+RemoteStorageHelper.forceDelete(storage, bucketName, 5, TimeUnit.SECONDS);
+}
+}
 }