Paradise Temporarily on Pause?

From the cross Jesus says to a criminal, “…today you will be with me in paradise.” From what I’ve read “paradise” seems to be a reference to “God’s garden,” which is itself an eschatological image of the new creation, but I’d love to learn more about “paradise.” (I know it shows up in 2 Corinthians 12:4 and Revelation 2:7 too.)

My real question is this: When did this criminal join Jesus in paradise? In other words, what are we to make out of the word “today”? Jesus was in the tomb until Sunday, so the criminal couldn’t have joined him in paradise “today.”

Is this just Luke’s unique way of emphasizing the immediacy of salvation? (Today salvation has come to this house… etc.)