In the SSPX, the External Solemnity of Saint Pius X may be celebrated this Sunday if it was not celebrated last Sunday.
Per the rubrics, one sung and one low Mass, or two low Masses, as votive Masses of the 2nd class, may be celebrated of the feast whose external solemnity is being held.
Mass of the Sunday, Gloria, Credo, preface of the Holy Trinity
For External Solemnity: Mass of St. Pius X; Gloria; commemoration of the Sunday; Credo; preface of the Holy Trinity
Office of Sunday per annum
Matins: Invitatorium and Hymn per annum as given in the psalter; three lessons proper; Te Deum
Lauds: Antiphons and psalms of Sunday (first schema); remainder per annum as given in the psalter; Benedictus antiphon and oration proper
Hours: Antiphons and psalms of Sunday (at Prime, Psalm 117 is used); remainder per annum as given in the psalter; oration proper
II Vespers: Of the Sunday per annum as given in the psalter; Magnificat antiphon and oration proper
Compline: Of Sunday