It is intended that the CDM Regulations 2015 will come into force on 6 April 2015 (Easter Monday). This means that the last working day before they come into force will be 2 April (Maundy Thursday). The Regulations include transitional provisions to cover projects which began before 6 April (effectively by 2 April) to cover the six-month period from 6 April to 6 October 2015.
If a CDM co-ordinator has been appointed before 6 April (effectively by 2 April), the appointment will continue to have effect for the purposes of the Regulations until the earlier of the project coming to an end and 6 October 2015. It would make sense for any such appointment to be formalised by 2 April.
If the project does not come to an end on or before 6 October, the client must appoint a principal designer before that date.
Schedule 4 to the Regulations, “Transitional and saving provisions”, details the duties of the CDM co-ordinator during the transitional period; the duties disapplied pending the appointment of a principal designer; and projects where there is only one contractor.