Time available on each of Gemini North and South is distributed according to the Observatory participants' shares. Engineering time is reserved each semester; this includes engineering time in the queue, instrument performance monitoring, engineering time to accommodate visiting instrumentation, and instrument commissioning. Any unused engineering time is returned to science. The science time includes time used for all Observing Modes, including standard semester programs (this call), Large and Long programs, Fast Turnaround programs, and Director's Discretionary time. Time for limited-term partners is also reserved from the total science time each semester. The estimated time available for each participant and host institution is shown below. The 2021A time distribution applies no balancing of partner executed time, and assumes that participants involved in Large and Long Programs take their full 20%.
| Participant | Estimated Science Time Available (hours) | Time Reserved for Fast Turnaround programs (hours) [A] | Time Reserved for Large and Long Programs (hours) [B] | Estimated Time Available for this Call (hours) [C] |
| US | 1031 | 103.1 | 91 | 781 |
| Canada | 272.9 | 27.2 | 24 | 224 |
| Argentina | 46.6 | 4.7 | 0 | 39 |
| Brazil | 98 | 9.8 | 0 | 83 |
| Korea | 75.2 | 7.5 | 0 | 64 |
| Univ. of Hawaii (host) | 169.2 | 16.9 | 0 | 163 |
[A] - 10% of the available time is contributed by all participants and host institutions to the Fast Turnaround program.
[B] - Up to 20% of the available time is contributed by the United States, and Canada, to Large and Long Program.
[C] - As this time also includes weather loss and time lost to faults, approximately 80% of this time is allocated to programs during the ITAC process (~30% in Band 1, ~30% in Band 2 and ~20% in Band 3).
| Participant | Estimated Science Time Available (hours) | Time Reserved for Fast Turnaround programs (hours) [A] | Time Reserved for Large and Long Programs (hours) [B] | Estimated Time Available for this Call (hours) [C] |
| US | 865.4 | 87.0 | 79.7 | 655 |
| Canada | 229.1 | 22.9 | 21.1 | 186 |
| Argentina | 39.2 | 3.9 | 0 | 33 |
| Brazil | 82.2 | 8.2 | 0 | 70 |
| Korea | 63.1 | 6.3 | 0 | 54 |
| Chile (host) | 142.1 | 0 | 0 | 142 |
[A] - 10% of the available time is contributed by all participants and host institutions to the Fast Turnaround program.
[B] - Up to 20% of the available time is contributed by the United States, and Canada, to Large and Long Program.
[C] - As this time also includes weather loss and time lost to faults, approximately 80% of this time is allocated to programs during the ITAC process (~30% in Band 1, ~30% in Band 2 and ~20% in Band 3).