sabbatical

As nouns the difference between hiatus and sabbatical

is that hiatus is a gap in a series, making it incomplete while sabbatical is an extended period of leave, often one year long, taken by an employee in order to carry out projects not otherwise associated with the employee's job. During the sabbatical, the employer may pay some or all of the wages that would have been otherwise earned or some or all of the expenses incurred. University lecturers, for example, may be granted a one-year paid sabbatical once every seven years.

As an adjective sabbatical is

relating to the Sabbath.

As adjectives the difference between abbatical and sabbatical

is that abbatical is (obsolete) while sabbatical is relating to the sabbath.