Unexpected Rationalussy Paradox

Eliezer Yudkowsky promises you that he will tweet the word "rationalussy" at some point in the year 2023, but that the day will be a surprise, such that you won't know what day he will tweet it until he in fact posts the tweet. Furthermore, to avoid fake solutions that don't actually get to the heart of the paradox, he will not do it at midnight on any day. You reason that he cannot post the tweet on Dec. 31, since then you would know what day he is going to post it as soon as the clock strikes midnight. However, since he won't post it on Dec. 31, he can't post it on Dec. 30, either, since you would know at midnight on Dec. 30 that this is the last possible day he can post it, having already eliminated Dec. 31. You continue this chain of reasoning to conclude that Yudkowsky cannot write the tweet on any day in 2023, and thus, he cannot keep his promise. Then he tweets it on [date undisclosed], which is a total surprise to you, thus keeping his promise after all.