Rev. Rul. 56-24

The word `day' as used in relation to article XI(1) of the income tax convention between the United States and the United Kingdom of Great Britain and Northern Ireland, T.D. 5569, C.B. 1947-2, 100, with respect to the exempt status of compensation for personal services performed by a resident of the United Kingdom who is present in the United States for a period or periods not exceeding in the aggregate 183 days during the taxable year, is interpreted for United States income tax purposes to mean a day during any portion of which the resident of the United Kingdom was physically present within the United States. This interpretation will apply equally to all income tax conventions containing similar provisions.

I.T. 3876, C.B. 1947-2, 120, supplemented.