"Then at Belshazzar's command, Daniel was clothed in purple, a gold chain was placed around his neck, and he was proclaimed the third highest ruler in the kingdom." NIV translation
The king kept his promise to Daniel and elevated him to be his second in command. As we saw before, the king was really subject to his father who was off at war and so, in effect, Daniel became the third highest official in the kingdom. As is the pattern with God, He elevates the humble servant (Daniel).
"That very night Belshazzar, king of the Babylonians, was slain, and Darius the Mede took over the kingdom, at the age of sixty-two." NIV translation
While the king was having his party, the Medes were already infiltrating the city. The judgment was carried out that very night and is a reminder to us that God has all of our days numbered. When He says it is time, then, your number is up.
As it was with King Belshazzar, we do not know when that appointed time is coming so we need to be prepared at all times. The only way to be prepared for the time when your number is up is through personal faith in Jesus Christ for your salvation.