What does Boxing Day have to do with boxing?
early 15c., "tutor, instructor" (earliest reference might be to "expert in the art of writing"), from Latin praeceptor "teacher, instructor," agent noun from praecipere (see precept). Medical training sense attested from 1803.
preceptorship pre·cep·tor·ship (prĭ-sěp'tər-shĭp')
A period of practical experience and training for a student, especially of medicine or nursing, that is supervised by an expert or a specialist in a particular field.
preceptor pre·cep·tor (prĭ-sěp'tər, prē'sěp'tər)
An expert or a specialist, such as a physician, who gives practical experience and training to a student, especially of medicine or nursing.