This is an aspect of appointments often overlooked. It is difficult to give a definite answer, unless the issue has been specified in the contract which defines the terms on which the teacher is engaged.
Characteristically, these contracts specify the proportion of full time which is to be worked, but leave the details of days and times open to negotiation, as the timetable changes year-on-year. The rule of thumb should be that part-timers are required to perform the non-teaching duties of teachers, including attendance at meetings, parents evenings, etc, pro rata, tking up the appropriate proportion of 1,265 hours.
Unless the contract specifies
otherwise, teachers are not entitled to assume that they are not obliged to attend on any particular working day, so that, if attendance at a training day falls within the contracted hours, it is a requirement.
Clearly, this may prove a problem for some people and negotiation is usually the common-sense approach.
In the end, teachers may have recourse to the grievance procedure, if they think that the head's direction is unreasonable.
Questions to Helpline, The TES, 66-68 East Smithfield London E1W 1BX. Archimedes regrets he cannot enter into individual correspondence