When do the first and second “hours” on Friday begin?
Question

                In the hadeeth about the virtue of coming early to Jumu’ah prayer it says that the one who comes in the first “hour” will have a reward like that of one who sacrifices a camel, and the one who comes in the second “hour” will have a similar reward. I hope that you can tell me when the first “hour” begins and ends, so that the second “hour” begins.
Praise be to Allah.
    It was narrated that Abu Hurayrah (may Allaah be pleased with 
    him) said: The Prophet  (peace and blessings of Allaah be upon him) 
    said: “Whoever comes (to the mosque) in the first hour, it is as if he 
    sacrificed a camel. Whoever comes at the second hour, it is as if he 
    sacrificed a cow. Whoever comes at the third hour, it is as if he sacrificed 
    a horned ram. Whoever comes at the fourth hour, it is as if he sacrificed a 
    chicken. Whoever comes at the fifth hour, it is as if he sacrificed an egg. 
    Then when the imam comes out, the angels come in to listen to the reminder 
    (khutbah).” 

    Narrated by al-Bukhaari, 841; Muslim, 850 

    The scholars differed as to the definition of these hours. 
    There are three opinions. 

    1 – That they start when dawn breaks

    2 – That they start when the sun rises. This is the view of 
    al-Shaafa’i, Ahmad, and others.

    3 – That these ‘hours’ all fall within one period of time, 
    which is after the sun has passed its zenith. This is the view of Maalik, 
    and was favoured by some of the Shaafa’is. 

    The third view is weak, and was refuted by many. 

    Al-Nawawi (may Allaah have mercy on him) said: 

    It is well known that the Prophet  (peace and blessings 
    of Allaah be upon him) used to go out to offer the Jumu’ah prayer straight 
    after the sun passed its zenith, as do all imams in all regions. That is 
    after the end of the sixth hour, which indicates that the one who comes 
    after the sun has passed its zenith has no share of guidance and virtue, and 
    no reward will be recorded for him at all, because he has come after the 
    scrolls (of the recording angels) have been rolled up. The mention of these 
    hours is intended only to encourage people to come early and attain the 
    reward of being in the first row and waiting for the prayer, and keeping 
    busy with naafil prayers, dhikr and the like. None of that can be achieved 
    by going to the mosque after the sun has passed its zenith, and there is no 
    virtue in doing so, because the call to prayer is given at that time and it 
    is haraam to delay responding to it. End quote. 

    Al-Majmoo’, 4/414 

    Ibn Qudaamah (may Allaah have mercy on him) said: 
With regard to the view 
    of Maalik that goes against these reports: it is mustahabb to perform 
    Jumu’ah prayer just after the sun has passed its zenith. The Prophet  
    (peace and blessings of Allaah be upon him) used to pray Jumu’ah early, and 
    when the imam comes out the scrolls (of the recording angels) are rolled up, 
    and no reward is written down for the one who comes to Jumu’ah prayer after 
    that, so what virtue can there be in such a person? End quote. 

    Al-Mughni, 2/73 
The correct view is the 
    second one, which says that these hours begin when the sun rises, and the 
    time between sunrise and the second adhaan should be divided into five 
    parts, of which each one is what is meant by the word saa’ah (lit. “hour”) 
    in the hadeeth. 

    Shaykh Muhammad ibn Saalih al-‘Uthaymeen (may Allaah have 
    mercy on him) was asked: 

    When does the first hour of Friday begin? 

    He replied:

     The hours which were mentioned by the Prophet  (peace 
    and blessings of Allaah be upon him) are five. He said: “Whoever comes (to 
    the mosque) in the first hour, it is as if he sacrificed a camel. Whoever 
    comes at the second hour, it is as if he sacrificed a cow. Whoever comes at 
    the third hour, it is as if he sacrificed a horned ram. Whoever comes at the 
    fourth hour, it is as if he sacrificed a chicken. Whoever comes at the fifth 
    hour, it is as if he sacrificed an egg. Then when the imam comes out, the 
    angels come in to listen to the reminder (khutbah).” So the time between 
    sunrise and the imam’s arrival is divided into five parts, each of which may 
    be equivalent to what we know as an hour (sixty minutes), or it may be more 
    or less, because time changes. So there are five hours between sunrise and 
    the imam’s arrival for the prayer, starting at sunrise. It was also said 
    that it begins at the break of dawn, but the first view is more correct, 
    because the time before sunrise is the time for Fajr prayer. End quote. 

    Majmoo’ Fataawa al-Shaykh Ibn ‘Uthaymeen, 
    16; question no. 1260 

    For more details on this issue, please see Zaad al-Ma’aad 
    by Ibn al-Qayyim, 1/399-407. 

    And Allaah knows best.