With two "versions" of Office available, click-to-run or MSI, many users are confused when the monthly updates are released but won't install on their computer, reporting that the user doesn't have the expected version of Office installed. This is because these users have a click-to-run version, such as Home Premium or Professional installed, and the downloadable updates listed in the KB articles are for the MSI installation, available only with volume licenses and MSDN/TechNet subscriptions. Additionally, Office 2013 RT is on its own update schedule.
Users with click-to-run installations, which is pretty much everyone, will receive the updates from Microsoft update as they are released. Updates should be be automatically downloaded and installed, but you can check to see if any are waiting. Open Outlook and look on the File menu, Office Account, Office updates. When the Office updates button is yellow, an update is waiting to be installed. You can click to install or wait for windows to install it on the next reboot.
The updates for click to run versions are a month or two behind the MSI updates. This week's update for click-to-run includes the To-do Bar fix that the MSI version received a few weeks ago. With this week's update installed, the To-Do Bar displays all appointments for the next 7 days in either the To-Do Bar or the Calendar Peek. After installing the update, Outlook 2013 is at v15.0.4551.1005.