# MongoDB\Driver\Session::advanceClusterTime

(mongodb >=1.4.0)

MongoDB\Driver\Session::advanceClusterTime — Advances the cluster time for this session

### Description

final public MongoDB\Driver\Session::advanceClusterTime ( array|object `$clusterTime` ) : void

Advances the cluster time for this session. If the cluster time is less than or equal to the session's current cluster time, this function is a no-op.

By using this method in conjunction with MongoDB\Driver\Session::advanceOperationTime() to copy the cluster and operation times from another session, you can ensure that operations in this session are causally consistent with the last operation in the other session.

### Parameters

`clusterTime`

  The cluster time is a document containing a logical timestamp and server signature. Typically, this value will be obtained by calling MongoDB\Driver\Session::getClusterTime() on another session object.

### Return Values

No value is returned.

### Errors/Exceptions

- Throws MongoDB\Driver\Exception\InvalidArgumentException on argument parsing errors.

### See Also

- MongoDB\Driver\Session::advanceOperationTime() - Advances the operation time for this session
- MongoDB\Driver\Session::getClusterTime() - Returns the cluster time for this session