Short answer
Not for certain. The Prophet ﷺ told us to seek it in the odd nights of the last ten. The 27th is the night most hoped for, because Ubayy ibn Ka'b swore it was the 27th and many Companions and scholars agreed. But it was deliberately hidden, and many scholars hold that it moves between the last ten nights from year to year. Worship on every night.
Most Hanafi scholars hold that Laylatul Qadr is in Ramadan and most likely the 27th night. Abu Hanifa's well-known view is that it lies within Ramadan without a fixed night, moving from year to year (another report from him says it can fall in any part of the year). Either way, the safe practice is to worship in all of the last ten nights.
Other madhhabs
- Shafi'i
- Imam al-Shafi'i inclined to the 21st or 23rd night, and many Shafi'i scholars say it moves among the odd nights of the last ten.
Explanation
Allah says Laylatul Qadr (the Night of Decree) is better than a thousand months. The Prophet ﷺ said: seek Laylatul Qadr in the odd nights of the last ten of Ramadan. He once came out to tell the people its date, but two men were arguing and the knowledge of it was taken away, and he said that perhaps this was better for them.
Why the 27th? Zirr ibn Hubaysh asked Ubayy ibn Ka'b about it. Ubayy swore, without making any exception, that it was the 27th night, and said he knew it by the sign the Prophet ﷺ had given: the sun rises the next morning white, without strong rays. Ibn Abbas and others also leaned to the 27th, and it became the most popular view.
Why not only the 27th? Other authentic reports point to the 21st and the 23rd in particular years. Many scholars combine them by saying the night moves among the last ten. Since the 27th is a date in the Hijri calendar, and countries start Ramadan on different days, the 27th in one place may be the 26th or 28th in another, which is another reason not to rely on one night.
- Worship on all of the last ten nights, as the Prophet ﷺ did.
- Give the odd nights extra effort, and the 27th the most.
- Do not stay up only on the 27th and sleep through the rest.
See how to pray on Laylatul Qadr, is tonight Laylatul Qadr and Laylatul Qadr.
The evidence
Quran, Surah Al-Qadr 97:3
لَيْلَةُ ٱلْقَدْرِ خَيْرٌۭ مِّنْ أَلْفِ شَهْرٍۢ ﴿٣﴾
The Night of Decree is better than a thousand months.
The immense value of the night, which is why it is sought on every possible night.
Sahih al-Bukhari 2017
Sahih... تحروا ليلة القدر في الوتر من العشر الأواخر من رمضان ...
"Seek Laylatul Qadr in the odd nights of the last ten of Ramadan."
The night is sought among the odd nights of the last ten, not fixed to one.
Sahih Muslim 762
Sahih... هي ليلة صبيحة سبع وعشرين وأمارتها أن تطلع الشمس ...
"It is the night whose morning is the 27th, and its sign is that the sun rises white without rays."
Ubayy ibn Ka'b's sworn view that it is the 27th.
Where the ruling is recorded
- Radd al-Muhtar (Ibn Abidin), Kitab al-Sawm, chapter on itikaf. The views on Laylatul Qadr, including that it is the 27th and Abu Hanifa's view that it moves within Ramadan.
- al-Majmu' (Nawawi), Kitab al-I'tikaf, section on Laylatul Qadr. The Shafi'i views on which night is most likely.
Checked by our team. For a more accurate answer to your own situation, consult a scholar. Quran translation by Sahih International. Hadith Arabic from the standard editions of the six books and the Muwatta, with gradings as recorded there; the English is our own rendering. Spotted a mistake? Tell us.