Today's first reading at Mass reminded me of the vision of Leo XIII.
"[The angel] seized the dragon, the ancient serpent, which is the Devil or Satan, and tied it up for a thousand years and threw it into the abyss, which he locked over it and sealed, so that it could no longer lead the nations astray until the the thousand years are completed. After this, it is to be released for a short time." - Book of Revelation
How long is a thousand years in biblical terms, or "a short time" for that matter?