We assume that you're using Strategic 1-year Objectives and Tactical Quarterly Objectives. Here's how the cycle should look like if you're starting with the new year.
4-6 weeks before the end of the year [Nov 20-30]
The top management brainstorms the priorities for the next year and puts together the draft of the strategy. It is highly recommended to share it publicly and gather the input and feedback from all levels of the organization.
2-3 weeks before the end of the year [Dec 10]
Finalize your company-wide Objectives for the next year and the next quarter. Communicate them to everyone. Now each team should set their Objectives based on the company Objectives, using a bi-directional approach.
1 week before the end of the year [Dec 20]
Gather the all-hands or strategic meeting during which you finalize the Objectives, synchronize with each other, and make final adjustments if needed. Map interdependencies and make sure to align with other teams and initiatives.
It's crucial to create a public commitment for each team by making their OKRs public for the team. Communicate the high-level company OKRs again.
Don't be afraid to overcommunicate!
2 weeks into the period [Jan 15]
Track progress and conduct weekly or bi-weekly check-ins with your team, during which you'll share high-level progress during the last week or two. They should be short, don't do the full review of all Objectives.
6 weeks into the period (Middle Check-in) [Feb 15]
Conduct a longer (2-3 hours) check-in with your top management and with your teams internally to update progress and discuss how the team is moving so far. Score your Objectives, and adjust/change your course if necessary.
3 weeks before the end of the quarter [March 10]
Brainstorm with your top-management the company-wide priorities for the next quarter. Again, involve all levels of the organization into the discussion. Make sure to align them with your yearly Strategic Objectives. Communicate your upcoming quarter Objectives with the team.
1 week before the end of the quarter [March 25]
Teams create their Objectives based on the company tactical and their yearly Objectives. Each team scores its Objectives, conducts the retrospective how the period went, reflect on what went right and what should be improved.
End of the quarter [April 01]
Conduct another all-hands or strategic meeting during which you'll finalize the OKRs and communicate them between all teams and departments.