The signs by which Laylat al-Qadr is known
The first sign: it was reported in Saheeh Muslim from the hadeeth of Ubayy ibn Ka’b (may Allaah be pleased with him) that the Prophet (peace and blessings of Allaah be upon him) announced that one of its signs was that when the sun rose on the following morning, it had no (visible) rays. (Muslim, 762).
The second sign: it was reported from the hadeeth of Ibn ‘Abbaas narrated by Ibn Khuzaimah, and by al-Tayaalisi in his Musnad, with a saheeh isnaad, that the Prophet (peace and blessings of Allaah be upon him) said: “Laylat al-Qadr is a pleasant night, neither hot nor cold, and the following day the sun rises red and weak.”(Saheeh Ibn Khuzaymah, 2912; Musnad al-Tayaalisi).
The third sign: it was reported by al-Tabaraani with a hasan isnaad from the hadeeth of Waathilah ibn al-Asqa’ (may Allaah be pleased with him) that the Prophet (peace and blessings of Allaah be upon him) said: “Laylat al-Qadr is a bright night, neither hot nor cold, in which no meteors are seen.” Narrated by al-Tabaraani in al-Kabeer. See Majma‘ al-Zawaa’id, 3/179; Musnad Ahmad).
These three saheeh ahaadeeth explain the signs which indicate Laylat al-Qadr.
It is not essential for the one who “catches” Laylat al-Qadr to know that he has “caught” it. The point is to strive hard and to be sincere in worship, whether or not one knows that one has “caught” it. It may be that some of those who do not know that may be better with Allaah and higher in status than those who did know which night it was, because the former strove hard. We ask Allaah to accept our fasting and our prayer at night, and to help us to remember Him and to thank Him and to worship Him properly. May Allaah bless our Prophet Muhammad.