Praise be to Allah.
The time for Jumu’ah lasts until the time for ‘Asr begins, according to the majority of scholars. If the people pray Jumu’ah before the time for ‘Asr begins, then they have caught up with Jumu’ah.
See: al-Majmoo’ (4/377-381), al-Muhalla (5/42-45).
It is better to pray Jumu’ah with those who offer the prayer at the beginning of its time, because that is in accordance with the Sunnah of the Messenger (peace and blessings of Allaah be upon him). It was narrated that Salamah ibn al-Akwa’ (may Allaah be pleased with him) said: We used to pray Jumu’ah with the Messenger of Allaah (S) when the sun passed its zenith . Narrated by al-Bukhaari (4168) and Muslim (860).
It is haraam to delay Jumu’ah until the time for it is over; that is a major sin, because Allaah says (interpretation of the meaning):
“Verily, As‑Salaah (the prayer) is enjoined on the believers at fixed hours”
“Then, there has succeeded them a posterity who have given up As‑Salaah (the prayers) [i.e. made their Salaah (prayers) to be lost, either by not offering them or by not offering them perfectly or by not offering them in their proper fixed times] and have followed lusts. So they will be thrown in Hell”
The scholars of the Standing Committee for Issuing Fatwas were asked about people who are studying in the US, and the study program does not allow any time for prayer. The time for Jumu’ah prayer in the US is 1.30 p.m., but they are forced to delay it until 4 p.m. because of the study program. Is it permissible to delay Jumu’ah until this time?
They replied: It is not permissible to delay the five prayers for which the wise Lawgiver has stipulated specific times. If the delay in prayer is for a reason which will not cause one to miss its prescribed time, then it is permissible to delay it; if it will cause one to miss the time, it is haraam. If continuing to study means that the prayer will be done outside of the proper time, then it is not permissible for the student to do that, and he must offer the prayer on time. The end of the time for Jumu’ah is the end of the time for Zuhr, so it is not permissible to delay it under any circumstances.
And Allaah is the Source of strength. May Allaah s end blessings and peace upon our Prophet Muhammad and his family and companions. End quote.
Shaykh ‘Abd al-‘Azeez ibn “Abd-Allaah ibn Baaz, Shaykh ‘Abd al-Razzaaq ‘Afeefi, Shaykh ‘Abd-Allaah ibn Qa’ood.
Fataawa al-Lajnah al-Daa’imah (8/197).
To sum up:
It is permissible to delay Jumu’ah prayer until close to the time for ‘Asr, in such a way that it will end before the time for ‘Asr begins, but if there is more than one Jumu’ah in the town, it is better to pray with those who pray Jumu’ah when the time for it begins.
And Allaah knows best.