public Builder setRdbSnapshotStartTime(
          com.google.protobuf.Timestamp.Builder builderForValue) {
        if (rdbSnapshotStartTimeBuilder_ == null) {
          rdbSnapshotStartTime_ = builderForValue.build();
        } else {
          rdbSnapshotStartTimeBuilder_.setMessage(builderForValue.build());
        }
        bitField0_ |= 0x00000002;
        onChanged();
        return this;
      }
<pre>
Optional. Time that the first snapshot was/will be attempted, and to
which future snapshots will be aligned. If not provided, the current time
will be used.
</pre>

<code>
.google.protobuf.Timestamp rdb_snapshot_start_time = 2 [(.google.api.field_behavior) = OPTIONAL];
</code>
java-valkey/proto-google-cloud-valkey-v1/src/main/java/com/google/cloud/memorystore/v1/PersistenceConfig.java