Lag Calendar, in Planner Language

Lag is hours on the link (lag_hr_cnt). Which calendar walks those hours is a project schedule option, not a per-relationship pick. Oracle’s four choices: Predecessor Activity Calendar, Successor Activity Calendar, 24-hour Calendar, or Project Default Calendar. If the option is left unset, Oracle uses the successor calendar.

That is a different sentence from “lag typed in days is converted to hours on the predecessor calendar.” Conversion is how the number gets into hours. The schedule option is whose workweek then consumes those hours (a 5×8 pred vs a 7×12 succ will place the same +2d lag on different clock dates). Do not invent the XER codes for the option; the column is sched_calendar_on_relationship_lag and Oracle does not list the stored values.

Detail: Calendar Used for Relationship Lag. Types and +lag/−lead: FS / SS / FF / SF + Lag (Planner Language).