Universitat Oberta de Catalunya Universitat Oberta de Catalunya Universitat Oberta de Catalunya Inria This specification defines an optional extension to the Constrained Join Protocol (CoJP) defined by the Minimal Security Framework for 6TiSCH. The extension aims at providing global time distribution support so nodes in the 6TiSCH network can exploit global time information instead of relying only in relative network time based on the Absolute Sequence Number (ASN). The specification also defines a mechanism for resynchronization, to handle leap seconds or to enable periodic global time updates relying on a CoAP service.