Interpretation Act 2005 section 16

Commencement

Section 16 sets out the rules for determining when Acts and statutory instruments come into operation.

• By default, every provision of an Act comes into operation on the date it is passed by the Oireachtas.
• If an Act specifies a particular commencement day, the provision actually takes effect at the end of the day before that specified day — meaning it is in force from the start of the named day.
• By default, every provision of a statutory instrument comes into operation at the end of the day before the day it is made.
• If a statutory instrument specifies a particular commencement day, it takes effect at the end of the day before that specified day, regardless of whether the day is before or after the date the instrument was made.