Article 50 does allow Britain to negotiate a transitional period

The PM intends to negotiate a transitional period after March 2019, during which people, businesses and services would have time to adapt to Brexit while the current regulatory framework is maintained. But it is still unclear how Britain will do this. Federico Ortino and Holger Hestermeyer (King’s College London) argue that Article 50 allows the UK to postpone the beginning of the withdrawal agreement until a later date – perhaps March 2021. This would give the government valuable time to implement Brexit.