Corrected entry: When Travis is with the gun salesman, he is trying out the black gun. You see a close up shot of him holding the gun with his arm outstretched with his jacket on. In the very next shot (no time has elapsed) his arms are at his side and his jacket is now completely off. (00:56:50)
Corrected entry: In the brothel shoot-out at the end, Travis gets shot in the neck and has a pretty nasty wound - but when we see him a few days/weeks later there's no sign (scab or scar etc.) of the bullet wound on the left hand side of his neck.
Correction: There is a visible scar on the left side of Travis's neck. You can see it in all of the ending scenes (when he's talking to his fellow taxi drivers and when he's driving).
Corrected entry: After Travis shoots Sport, he walks over and sits on the left side of the stairway. Then in the next shot, you see him walking up the stairs from the right side.
Correction: The stairway to a building that he sits on is not the same building that he walks into. You can tell by the front door of the buildings. The first building has the number 208 on the glass. The building that he walks into, doesn't have any numbers.
Corrected entry: The back window of the taxi gets broken out, then reappears unbroken when driving back to the taxi cab station.
Correction: The back window is not broken. Whatever liquid was in one of the bottles explodes out onto the window.
Corrected entry: At one point when Travis is in his room doing what he does he rips the arm off his white shirt. A minute later, the sleeve is back on.
Correction: We can assume that the shirt Travis has on at the end of the scene is a new, different shirt than the one that he cut the sleeve off. The cut shirt is for his plan against the Senator.
The whole scene shows him preparing for what he melodramatically wants to be his last heroic gesture. We see him sharpen the knife, cut the sleeve with it, and strap the knife to his boot, and write a farewell letter telling Iris that he'll be dead when she reads it. It can't be another shirt. He's not changing shirts to write that letter.
Corrected entry: When Robert DeNiro attempts to kill the senator, it is June according to his diary entry, and he has a mohawk. He still has the mohawk later on at the hotel shoot out. In the last scene of the movie his hair is fully grown in. In the conversation with Cybil Shepard we learned the senator received the nomination for president. That had to take place at the party's convention no later than August in the same year.
Correction: Just because Palantine was nominated in August doesn't mean that this scene takes place in August. Bickle hasn't seen Betsy since he was shot. It could be several months later.
Actually, no. The dialogue explicitly says through Betsy, when Travis brings up that he heard that the Senator got the nomination; "It won't be long now. Seventeen days." So, in that context, it would mean that he will officially receive the nomination in seventeen days at the convention. It can't be "several months later."
She doesn't correct him about already getting the nomination. I interpreted the line to mean it was 17 days to the election.
Mid-October then? Hm, the leaves are bright green and everyone wears the same clothes as the rest of the movie including Charlie in a tanktop, and passersby in just shirts with rolled sleeves and polos, at night in NY. As far as the statement goes, the comment is right, it can be easily read that way too, it's just that the context does not seem to fit well.
Correction: I am really not sure about the "no time has elapsed" bit. Everything about the setup leads to believe time has indeed passed. He has the gun in his pants and he is checking himself out in the mirror, which is why he removed the jacket and his arm is in a different position. The differences are so many that it's not an awkward mistaken transition or edit hiccup, it's a jump ahead in time, on purpose.
Sammo ★
This is verified by Scorsese on the commentary he recorded for the laserdisc release. He specifically states it was a jump cut to speed up the action.