By default all banners from the Notification Center stays 5 seconds on your screen. You can adjust how long Notification Center banners are shown before they disappear. To do this use the following command in OS X Terminal:
Unveil hidden macOS (OS X) features
By default all banners from the Notification Center stays 5 seconds on your screen. You can adjust how long Notification Center banners are shown before they disappear. To do this use the following command in OS X Terminal: