The Ruling on speaking on Fridays
Question :
Is it permissible to address the people on Fridays at 'Asr time? Benefit us, and may Allah benefit you.
Answer
Yes, it is permissible to address the people at 'Asr time, or Maghrib time and at all times, because lecturing and reminding people (of Allah) is knowledge, a form of advice, and beneficial to the listeners. There is no obligation upon anyone to attend, nor is there any evidence that it is disliked, although the people are accustomed to taking Friday off from their work or studies, but even so, there is no objection to it, Allah willing.
Source:
Ibn Jibreen
Fatawa Islamiyah, Vol. 1 Pages 377