CORRECT especially American EnglishAmE informal exactly right, or at exactly the right time 非常准确；准时
She got to our house at two, on the button.
她两点钟准时到了我们家。
Examples from the Corpus
on the button• She clicked on the button to turn over the second card, and the second card was Death.• So she pressed down on the button more firmly.• Did he bank and dive, his finger on the button, his guns blazing from the wings?• The whole show, Dominic says, is about keeping your finger on the button.• He was pressing hard on the button and standing patiently for the door to open.• He made his birdie and he made his cut, right on the button.• The weather forecast was right on the button.• She got to our house at two, on the button.