The possibility of doing your PhD part-time is included, both in the national regulations, article 3 of Royal Decree 99/2011, and in points 3 and 5 of the institutional regulations.
The application to study part-time can be made at the time of requesting admission (pre-registration) or later, once the enrollment is done (through the student's UPV INTRANET: Secretaría Virtual – Matrícula a Tiempo Parcial).
Once the application has been approved by the Academic Committee of the program, the partial time dedication will be maintained in future enrollments, unless requested otherwise.