The feature window is now
While the feature window is open, we allow merging new features and changes. Normally, the feature window is open from the Monday following a release until the Wednesday four weeks before a pending release.
While the feature window is closed, we do not allow merging new features or changes and only merge bug-fixes.
You can still submit pull-requests for new features when the window is closed, but they will not be merged until the window opens again.