Each Salat must be offered at or during its proper time.
No Salat can be offered before its time. There are five obligatory Salat in a day.
Fajr Prayer (Morning Prayer)
The time for the Fajr or the morning prayer starts at dawn and ends at sunrise.
Dhuhr Prayer (Early Afternoon Prayers)
The time for Dhuhr or the early afternoon prayer starts when the sun begins to decline from its zenith an and ends when the size of an object's shadow is equal to the size of the object.
Jaber bin Abdullah narrated: The angel Jibrael came to Prophet Muhammad (pbuh) and said to him, "Stand up and pray Thuhr". So Allah's Messenger (pbuh) prayed Thuhr when the sun had declined from its zenith . Then the angel Jibrael came again at the time of Asr and said "Stand up and pray Asr". Then Prophet Muhammad (pbuh) prayed Asr when the shadow of everything was equal to itself. Then Jibrael came the next day to Prophet Muhammad (pbuh) and said, (after praying 10 Salat with Prophet Muhammad (pbuh) in two consecutive days) that the time of Salat (prayer) is in between these two times.
Ahmad, Nasai, Tirmidhi and Bukhari remarked that this is the most authentic Hadith giving the times of prayer. We find that many books on Salat state the ending time of Dhuhr prayer and the starting time of Asr prayer when the shadow of something is twice itself. But this contradicts the above Hadith as on the first day Jibrael asked Prophet Muhammad (pbuh) to pray Asr when the shadow of everything was equal to itself. This means that was the end time of Dhuhr prayer. And we already know that all the Ulama of the Muslim Ummah(Scholars) agree unanimously that no Salat (prayer) can be offered before its time.
The time for Asr or late afternoon prayer starts when the shadow of something is equal to itself and ends just before sunset.
It is better to offer Asr prayer before the sun becomes yellow because even though it is allowed to offer the Salat (prayer) at this time the Prophet (pbuh) disliked Muslims to delay Asr prayer up to this time. He remarked that the Munafiq (hypocrite) offered his Salat (prayer) at this time.
The time for the Maghrib or the sunset prayer starts just after sunset and ends when twilight has disappeared. Isha Prayer
The time for Isha or night prayer starts from the disappearance of twilight and ends just before midnight.
It is preferable to offer this Salat (prayer) before midnight but it can be offered right up to the break of dawn.
Note: In countries where due to cloudy weather the sun is not always visible, it is advisable to follow printed calendars giving the accurate time of each Salat (prayer).
Forbidden times of Prayer
Uqbah bin Amir said, There were three times at which Allah's Messenger (pbuh) used to forbid us to pray or bury our dead:
(i) When the sun began to rise until it was fully up.
(ii) When the sun was at its height at midday till it passed the meridian.
(iii) When the sun drew near to setting till it had set. (Muslim)
Forbidden Times for Nafl Prayer (i) Abu Saeed AlKhudree reported Allah's Messenger (pbuh) as saying, No Salat is to be said after the Fajr prayer until the sun rises, or after the Asr Prayer until the sun sets. (Bukhair and Muslim)
Only Nafl prayer is forbidden at these times but a missed Fard prayer can be offered. Most of the Ulama of the Muslim Ummah allowed the offering of missed Fard prayer after Fajr and Asr because of the following Hadith:
Prophet Muhammad (pbuh) said, Who has forgotten the prayer he should pray it whenever he remembers it. (Bukhari and Muslim)
(ii) A Nafl prayer cannot be offered once the Iqamat for Fard prayer has been said. Abu Hurairah narrated that Allah's Messenger (pbuh) said, When the Iqamat has been said, then, there is no Salat valid (Nafl or Sunnat ) except the Fard prayer for which the Iqamat was said. (Ahmad and Muslim)
It is seen in practice that many people continue with the Sunnat prayer even though the Iqamat has been said for the Fard prayer especially in the Fajr prayer. The feel that the 2 Raakat Sunnat of Fajr can only be offered before the Fard. This practice is against congregation philosophy, discipline of Jamaat, and a clear violation of Hadith. They should offer 2 Rakaat Sunnat of Fajr immediately after the Fard or after sunrise.
For Prayer Times for your City or Country please visit :http://www.islamicity.com/PrayerTimes/