But sometimes you don't eat the junk food because you've been eating junk food for the past week. Sometimes you stop procrastinating for a while because you've been procrastinating for the past month.

Thus your decision is affected by recent history, which is different every day. Still, if TDT considerations help one take up the strategy of not committing some vice if one hasn't committed it in in one's recent history, that's very useful.

(I've thought of these things before, and TDT hasn't cured me of akrasia)