The Bible has no punctuation in the original Old Testament manuscripts. This means that Luke 23 : 43 can be translated, “Truly I say to you, today you will be with me in paradise.”(NASB) or “Truly I say to you today, you shall be with me in paradise” (The Sacred Scriptures Bethel Edition). In other words, the location of the punctuation marks can either mean that either:
1) Today is the day on which I am telling you the following… or,
2) This is the very same day on which you will be with me in paradise.
The first option is correct. Confirmation can be found in John 20:17 where Jesus said to her (Mary) “Stop clinging to Me, for I have not yet ascended to the Father…” Given that Jesus said this to Mary three days after he died he clearly could not have gone to heaven on the day of the crucifixion. Thus, Jesus was clearly telling them that they would be with him in paradise with, no indication as to when.