If an employee reasonably holds a mistaken belief as to the correct EDT (resulting in late submission of the IT1), it is not reasonably practicable for him to present his claim for unfair dismissal within time. An extension of time should be granted.
When construing documents to see if they have an adverse impact on workers (in this case, a part-time worker who was not allowed to transfer to full-time work unless she agreed that the transfer was temporary), tribunals should not adopt a contra proferentum approach but should examine the document against the background facts known to the parties at the time.