Jummah salaah before zawaal

As Salam alaikum mufti sahab,

I would like to know the validity of offering Jumma salat before Zawal time. It is getting very common in USA. Below is a link of justification given by one of the Islamic organization here:

http://mcmcnj.org/downloads/miscellaneous/JumahBeforeZawal.pdf

JazakAllah Khairan