I think its not a particular day called Juma, its just symbolic. Its congregation day every seventh day whatever calendar is used. ( Juma-majama- Ajmah- jameeat)
Therefore Friday or juma day isn't important.
I don't know why Muslim are not using lunar calendar when it comes to Friday, they are so particular about Ramadan or Eid days using telescopes, helicopters etc.
So its English Friday and Arabic Ramazan. Visual moon sighting with halal telescope and haram satellite. Alhomdillah.