What is the significance of "the Hour" among Arabs, and is it the hour we know today, based on the mention of the word "hour" in the Quran and the noble Hadith?

In the Arabic language, the word "Sa'ah" (الساعة) has two meanings: a part of the twenty-four parts of a day and night, or a small, unspecified portion of time. It was metaphorically borrowed to denote the Day of Judgment.