Java implements time calculation

1. Calculate the time difference between two

private long calculationTime(Date startTime, Date endTime) {
    
    
	LocalDateTime startDateTime = LocalDateTime.ofInstant(startTime.toInstant(), ZoneId.systemDefault());
	LocalDateTime endDateTime = LocalDateTime.ofInstant(endTime.toInstant(), ZoneId.systemDefault());
	Duration duration = Duration.between(startDateTime, endDateTime);
	long hours = duration.toHours();
	// long days = duration.toDays();
	// long minutes = duration.toMinutes();

	return hours;
}

2. Time offset

  
LocalDateTime now = LocalDateTime.now();
	//小时
	LocalDateTime afterOneHour = now.plusMinutes(1);
	//天数
	LocalDateTime afterDays = now.plusDays(1);
	//分钟
	LocalDateTime afterMinutes= now.plusMinutes(1);