Wikimedia Apps/Team/Development cycle

The mobile app develops software in two-week long sprints, or iterations. During the course of a development iteration, planning occurs for upcoming iterations.

Rationale
The team works in such a fashion in order to:
 * Keep the cost of change low (in all facets of the project - requirements, personnel, practices, etc)
 * Minimize risk by iteratively prioritizing requirements, closely examining/reevaluating the evolution of the product with the product owner and key stakeholders
 * Rapidly make adaptive changes as the product evolves
 * Increase productivity/limit context switching by focussing on a limited scope of small, manageable, discrete chunks of work
 * Measure and evaluate team capacity to aid in realistic estimation and create realistic expectations
 * Maintain a sustainable pace by limiting scope to the team's capacity

Regular planning meetings
There are a series of regular meetings to facilitate iteration planning. They are strictly timeboxed and facilitated by the scrummaster. Regular planning meetings are open to all, but are mandatory for some. The regular meetings are intended to balance the need for planning activities against the need for head's-down focus time for everyone on the team, and ultimately minimize the amount of expensive context-switching everyone on the team is exposed to.

This table captures the particulars of all regular planning meetings. Specific days of meetings are subject to change for scheduling conflicts, holidays, etc. Attendees are invited via Google calendar, where the definitive date/time of meetings is maintained.