The Property (Northern Ireland) Order 1997

2.  Where, in any entry in the second column of the Table, a lease is stated to be determinable, this is a reference to its being determinable by at least one month's notice served either by the lessor on the lessee or by the lessee on the lessor determining the lease on one of the quarter days specially applicable to the tenancy or, if there are no quarter days so applicable, on one of the usual quarter days.N.I.