Questioner: what is the ruling on using the Gregorian calender?

Sheikh Muqbil raḥimahullāh: It is considered blindfollowing [the Kuffār], and the Prophet ﷺ said, “Whoever imitates a people, then he is from them.” I advise to use the Hijri calendar. And Allāh is the One Whose aid is sought. Essentially brothers, they don't want to leave off any of the milestones of Islām, except that they want to eradicate them.