Not arguing with you, but it is quite unlikely that a Muslim would wish you, or anyone, a Happy Ramadan (because, as I said, it is a time of fast and penance.). Now, they might wish you a "Happy Eid," which are the days AFTER Ramadan when festing, eating, and parties prevail.
Ramadan is not the name of an Arabic or Muslim month. It moves, and is based on the Lunar Calendar. But because it lasts one lunar month, it is referred to as "the month of Ramadan." A few years ago Ramadan was in December-January. This year it was in October...having moved due to the lack of congruity between the lunar and solar/Gregorian calendar (that the modern world uses).
Lent, too is lunar based, although it lasts longer than a lunar month...it lasts 40 days.
I'm sure we're not at all disagreeing here.
A gentle suggestion, if I might.
I think I am correct when I say that there are many people who consider themselves to be a part of the modern world who do not use the Gregorian Calendar.
I have several close friends, for instance, who use a lunar calendar that is quite commonly used by Jewish people. They are, I assure, you, quite modern.
I also think I am correct when I say that the Islamic calendar does, in fact, have a month called Ramadan. But, because it is a lunar calendar, the month "moves" through the calendar that you and I use. However, if you are one of the people who uses the Islamic calendar, I think you could just as easily say that our solar calendar is what moves through the lunar calendar.