Date and hour

.of() .parse() .now()       plusDays, plusWeeks, plusMonths, plusYears minusDays, minusWeeks, minusMonths, minusYears isBefore, isAfter, isEqual Formatação de dados DateTimeFormatter ZonedDateTime  

🧠 Super resumo mental Duration → small units (hours/minutes) Period → big units (years/months/days) ✅ Duration Duration measures time in: hours minutes seconds It is used with: LocalTime LocalDateTime 👉 Think of Duration as clock-based time. Example: Duration.between(start, end); It calculates how much time passed between two times.   ✅ Period Period measures time in: years months days It is used with: LocalDate 👉 Think of Period as calendar-based time. Example: Period.between(startDate, endDate); It calculates the difference in years, months, and days.

 now(ZoneId) → quando quer hora de outro país now(ZoneId) → when you want the time of another country .now() Gets the current date or time from the system. .of() Creates a date/time by passing numbers. .parse() Converts a String into a date/time object   ✅ .now() → when you need the current moment You use it when the system needs to know: today’s date the current time the exact moment of a purchase whether something is overdue Real examples: LocalDate today = LocalDate.now(); LocalDateTime purchaseMoment = LocalDateTime.now();   📌 Commonly used in: payment systems due date verification logging systems   ✅ .of() → when you already know the values You use it when: you are creating a fixed date you are testing your code you are defining a specific rule LocalDate dueDate = LocalDate.of(2026, 5, 15);   📌 Commonly used in: unit tests system-defined dates calculated or predefined dates                                                                                         ✅ .parse() → when the date comes as TEXT You use it when: you receive a date from the user you receive a date from a database you receive a date from an API you read a date from a file   Example: LocalDate date = LocalDate.parse("2026-05-15"); 📌 Commonly used in: forms system integration JSON data processing

✅ plusDays() Adds days to a date. LocalDate newDate = date.plusDays(10); 👉 Adds 10 days. ✅ plusWeeks() Adds weeks to a date. LocalDate newDate = date.plusWeeks(2); 👉 Adds 2 weeks (14 days). ✅ plusMonths() Adds months to a date. LocalDate newDate = date.plusMonths(3); 👉 Adds 3 months. ⚠ Important: If the day does not exist in the new month, Java adjusts automatically. Example: LocalDate.of(2026, 1, 31).plusMonths(1); Result → 2026-02-28 ✅ plusYears() Adds years to a date. LocalDate newDate = date.plusYears(1); 👉 Adds 1 year.

LocalTime.parse(scanner.next(), formatter) → Para capturar o horário de entrada e saída no formato HH:mm. toHours() e toMinutesPart() → Para exibir a diferença de tempo em horas e minutos.