The ACA restriction listed in Appendix A.10 of the ALMA Cycle 4 Proposer's Guide need not apply to observations of phenomena with predictable times (such as maximum elongations of planets or planetary satellites), as long as the sum of their observability windows is spread over a sufficiently wide fraction of the Cycle 4 observing period, and, for monitoring projects, as long as the number of epochs that need to be observed remains relatively small with respect to the total number of suitable epochs across the Cycle.
Since observations defined as "time-constrained" in the OT are limited to one 12-m Array configuration (no ACA), users proposing such observations should not identify their projects as "Time Constrained" in the OT, but instead describe the details of the time requirements in their Technical Justification (e.g. how far apart in time the observations with the 12-m Array and ACA can be to still achieve the science objectives). If the time difference is too short, or of the project also requires multiple 12-m Array observations, the proposal may be rejected on technical grounds.
You can read how to include time constraints in the Observing Tool User Manual.
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