Hadith

369. A man asked the Prophet (sal Allahu alaihi wa sallam), "When will the Hour be established O Allah's Apostle?" The Prophet (sal Allahu alaihi wa sallam) asked, "What have you prepared for it?" The man said, "I haven't prepared for it much of prayers or fast or alms, but I love Allah and His Apostle." The Prophet (sal Allahu alaihi wa sallam) said, "You will be with those whom you love."
[Bukhari]

Commentary:
There are three important points to note here:

1. There is something more important than knowing when the Day of Judgment will occur. The more important thing is our preparation for that Day. What good or bad deeds have you sent forth for that Day? Each person's Judgment begins as soon as they die, and their grave becomes either a pit of fire or a garden of Paradise. Therefore, the most relevant thing to worry about are our daily deeds, as we never know when we will die and our Judgment commence.

2. The questioner in the hadith did the required (Fardh) prayers, fasts, and charity but not a whole lot extra. Some people do the opposite; they neglect the Fardh while doing a lot of the Sunnah (supererogatory). This is misguided because the greatest reward is for Fardh deeds and punishment is for neglecting the Fardh, not the Sunnah.