One of the more recent additions to OS X is Apple's Notification Center, which debuted in OS X Mountain Lion. This service offers a central place for notices such as new messages, update alerts, calendar alarms, or other messages a program may provide.
Notifications appear as either banners or alerts, which can be customized for some applications using the Notifications pane in System Preferences. While banners have no interaction controls and will only show for a brief time before disappearing, alerts will persist until you click the Close or "Snooze" button, the later of which will default to a delay of 10 minutes before the notification comes up again.
This default behavior was customary in OS X Mountain Lion, but could be somewhat limiting. While 10 minutes may be useful in some situations, you might otherwise wish to delay notices for only a few minutes, or perhaps for a day, or even a week. In Mavericks, Apple has changed this to now offer customizable times for notification snoozing; however, this feature is somewhat hidden.
While the notification center alerts in Mavericks still have the same Close and Snooze buttons, the Snooze button is now also a small menu, which can be invoked by clicking and holding the button. When you do this, you will see options for delaying the notice using set options ranging from a minute to a week in duration, or until the "end time" of the notice (such as the end of a calendar event).
Unfortunately Apple does not have a customization option where you can input your own delay time, such as 45 minutes, so you are still limited to the menu options, however, they now provide more than a single 10-minute snooze time.