San Juan and Miami share the same time during Eastern Standard Time (November to March). Both use UTC-5/-4 effectively. When it's 12:00 PM in San Juan, it's also 12:00 PM in Miami.
Puerto Rico does not observe daylight saving time. During Miami's daylight saving time (March to November), San Juan is 1 hour behind Miami as Miami moves to UTC-4 while San Juan stays at UTC-4.
Best calling time: 9:00 AM - 5:00 PM works well year-round. During DST, San Juan is 1 hour behind Miami.
San Juan and Miami have extremely strong connections. Miami is the main US gateway for Puerto Rico travel. The flight takes about 2.5 hours, and there are dozens of daily flights. Many Puerto Ricans have relocated to South Florida over the years.