Section 2(1)(c) in The High Court Judges (Salaries And Conditions Of Service) Act, 1954
(c)“actual service” includes—(i)time spent by a Judge on duty as a Judge or in the performance of such other functions as he may, at the request of the President of India, undertake to discharge;(ii)vacations, excluding any time during which the Judge is absent on leave;(iii)Joining time on transfer from a High Court to the Supreme Court or from one High Court to another or from the Supreme Court to a High Court;(iv)time spent by a Judge on duty as a Judge of a former Indian High Court;(v)time spent by a Judge to attend the sittings of the Supreme Court as an ad hoc Judge under article 127 of the Constitution; and(vi)vacation (excluding any time during which the Judge was absent on leave) taken by a Judge as a Judge of a former Indian High Court;