The Weekly Review is the lynchpin of the Getting Things Done system. It is an intentionally dedicated period of time (typically 30 minutes to 3 hours) in which you perform a routine set of standard organizational tasks.
the Weekly Review is the critical success factor for marrying your larger commitments to your day-to-day activities.” – David Allen, Getting Things Done
A week is short enough to control, but long enough to be flexible if any changes need to be made. It also allows us to see the bigger picture – how this week fits into our monthly, quarterly and yearly goals – and still stay focused at the same time. - Andrey Sergeyev
Demetri Martin's "If I..." stand up special contained an inspiring example of a weekly review as a sort of game.
Plan weekly, review daily - Weekdone