Ask and tell the time the Brazilian way (Que horas são? - São duas e meia da tarde) and make the verb agree with the number (É uma hora but São duas horas)
Name the days of the week as Brazilians count them (segunda-feira ... domingo) and say what happens on which day (na segunda, aos sábados, no fim de semana)
Read a Brazilian timetable written in 24-hour form (o voo sai às 14h30) and say it out loud the way people actually speak (duas e meia da tarde)
Use the contractions every calendar and clock phrase needs - do, da, no, na, ao, às, pelo - instead of the two separate words Russian would expect
Make the whole noun phrase agree: duas horas but dois minutos, os dias longos, as manhãs frias, meia hora but meio-dia