Work days : Monday through Friday
Bank Holidays : 1rst of January, Carnaval, Mardi Gras, 24th of March, 2nd of April, Good Friday, 1rst and 25th of May, 20th of June, 9th of July, 17th of August, 12th of October, 20th of November, 8th and 25th of December.
Time zone : UTC -3. In summer UTC-2 (only in some parts of the country)
Capital : Buenos Aires
Main Cities : Buenos Aires, Córdoba, Rosario, Mendoza, San Miguel de Tucumán.
Country Code : ISO 3166-2:AR

VAT : 21%
Currency : Argentine Peso (ARS)
Main Languages : Spanish 
Primary carrier service postal : Correo Argentino

Don't forget that for the calculation of your delivery delays, bank holidays are not considered work days.