In addition to Sunday, the days to be observed as holy days of obligation in the Latin Rite dioceses of the United States of America, in conformity with canon 1246, are as follows:

January 1, the solemnity of Mary, Mother of God (the Feast of the Circumcision in the 1962 Missal and Calendar)
Thursday of the Sixth Week of Easter, the solemnity of the Ascension
August 15, the solemnity of the Assumption of the Blessed Virgin Mary
November 1, the solemnity of All Saints
December 8, the solemnity of the Immaculate Conception
December 25, the solemnity of the Nativity of Our Lord Jesus Christ.

Ecclesiastic Feasts (Holy Days) (from the 1914 Catholic Encyclopedia)

Vatican Clarifies Holy Days and 1962 Missal

LONDON, APRIL 30, 2008 (Zenit.org).- The Vatican clarified the celebration of holy days of obligation when celebrating the extraordinary form of the Roman rite according to the 1962 Missal, reported the bishops' conference of England and Wales.

The episcopal conference submitted a query to the Pontifical Commission Ecclesia Dei, which confirmed that in the Roman rite, whichever form of the liturgy is being celebrated, the holy days of obligation are to be held in common.

Where the obligation has been removed and the holy day transferred to the Sunday, this is to be followed in both ordinary and extraordinary celebrations of Mass, the pontifical commission clarified.

Catholics are obliged to go to Mass on holy days of obligation. Some holy days of obligation vary according to the decisions made by local episcopal conferences.

There are differences in the calendars corresponding to the extraordinary and ordinary forms of the Mass, with many feast days falling on different dates in the two missals.