FACTS:

The consolidated cases involve petitions for mandamus and prohibition. The undisputed facts are as follows: Congress enacted Republic Act (RA) 7167, which adjusted the basic personal and additional exemptions for income tax purposes. The law was signed and approved by the President on December 19, 1991, and published on January 14, 1992, in "Malaya," a newspaper of general circulation. On December 26, 1992, respondents promulgated Revenue Regulations No. 1-92, which provided for the collection of income tax on compensation income under the revised withholding tax tables. On February 27, 1992, the petitioner in G.R. No. 104037 filed a petition for mandamus to compel the respondents to implement RA 7167 for taxable income earned or received from January 1, 1991. On February 28, 1992, the petitioners in G.R. No. 104069 filed a petition for mandamus and prohibition to compel the Commissioner of Internal Revenue to implement RA 7167 for income earned or received in 1991 and to enjoin the implementation of Revenue Regulations No. 1-92. The court consolidated the two cases and required respondents to comment. The principal issues to be resolved are whether RA 7167 took effect upon its approval or after fifteen days following its publication, and whether the law covers compensation income earned or received in 1991. In resolving the first issue, the court referred to a previous case involving the effectivity of a different law and held that laws shall take effect after fifteen days following the completion of their publication.

ISSUES:

1. Whether or not Rep. Act 7167 took effect upon its approval by the President or after fifteen days following its publication.

2. Assuming Rep. Act 7167 took effect on a later date, whether or not it applies to compensation income earned or received during calendar year 1991.

RULING:

1. Rep. Act 7167 took effect after fifteen days following its publication. The Court relied on the principle laid down in Tanada v. Tuvera that the clause "unless it is otherwise provided" in Article 2 of the Civil Code refers to the date of effectivity and not to the requirement of publication itself.

2. Rep. Act 7167 does not apply to compensation income earned or received during calendar year 1991. The Court held that the law clearly provides that it applies to income earned or received on or after January 1, 1992.

PRINCIPLES:

• Laws shall take effect after fifteen days following the completion of their publication in the official Gazette or in a newspaper of general circulation, unless otherwise provided. (Article 2, Civil Code)

• The date of effectivity of a law refers to the date it takes effect, and not the requirement of publication itself.

• The language of a law must be interpreted and applied as it is written.