Section 235(3) in The Building And Other Construction Workers '(Regulation Of Employment And Conditions Of Service) Central Rules, 1998
(3)Where a building worker employed in building or other construction work has worked on a rest day and has been given a substituted rest day on any one of the five days before or after the rest day, as provided in sub-rule (1) and sub-rule (2), such rest day shall, for the purpose of calculating the weekly hours of work, be included in the week in which such substituted rest day occurs.