Puerto Rico  uses the metric system. Gasoline is bought in liters (1 gallon = 3.7 liters), and distance is measured in kilometers (1 mile = 1.61 kilometers). The exception is speed, which is measured in miles per hour.
Puerto Rico observes Atlantic standard time and does not practice daylight saving time. Therefore, time in Puerto Rico is one hour later than Eastern standard time November–March and the same as Eastern daylight time from the second Sunday in March until the first Sunday in November.