Arab immigration to Argentina began in earnest in the 19th century, when Syrian and Lebanese families settled across the country in numbers large enough that an estimated 3.5 million Argentines trace some ancestry to the Levant today, though most identify as Christian. The country's Muslim population, put at roughly 400,000 to 500,000, is concentrated in Buenos Aires and its province and in Tucumán, and is served by the King Fahd Islamic Cultural Center in the Palermo district — built on land donated by then-president Carlos Menem and funded largely by Saudi Arabia. Buenos Aires also hosts the Islamic Organization of Latin America, which coordinates Islamic affairs across the wider region.
Argentina's territory runs from subtropical provinces bordering Bolivia down to Tierra del Fuego near Antarctica, a span of roughly 35 degrees of latitude that produces dramatically different day lengths at its extremes. Buenos Aires itself, in the temperate middle of that range, still experiences the full southern-hemisphere reversal of seasons — meaning its longest days fall in December and its shortest in June, the opposite of what a Northern-hemisphere calendar would suggest.
Congregations affiliated with the King Fahd center and the wider network coordinated by the Buenos Aires-based Islamic Organization of Latin America generally follow the Muslim World League's standard angles, which serve as the practical regional default in the absence of an Argentine national fatwa authority.
It is widely cited as such — its roughly 34,000-square-metre grounds in Palermo include the mosque itself, a library and two schools, making it the region's most prominent single Islamic complex.
Because Argentina sits in the southern hemisphere, June is midwinter there, so fasting hours are shorter than they would be during the same Islamic month observed in the northern hemisphere — the reverse holds for a Ramadan falling in the southern summer.
No — Tucumán sits roughly 8 degrees of latitude farther north and at a different longitude, so its Fajr, Dhuhr and Maghrib times diverge from the capital's by a noticeable margin even on the same date.
As at most congregational mosques, the Friday khutbah and prayer replace Dhuhr and are scheduled close to that day's calculated Dhuhr time, with the exact start set by the center itself.