我不知道棱角。我在下面回答了如何使用后端（您的Option-2 ）：

import java.time.LocalDateTime;
import java.time.ZoneId;
import java.time.ZonedDateTime;
import java.time.format.DateTimeFormatter;
import java.time.temporal.ChronoUnit;

public class Main {
    public static void main(String[] args) {
        String strBirthDay = "1996-07-24T00:00:00.000+0000";

        // Define formatter
        DateTimeFormatter formatter = DateTimeFormatter.ofPattern("yyyy-MM-dd'T'HH:mm:ss.SSSZ");

        // Define time-zone
        ZoneId zone = ZoneId.of("Etc/UTC");

        // Get dates
        ZonedDateTime birthDay = LocalDateTime.parse(strBirthDay,formatter).atZone(zone);
        ZonedDateTime zdtNow = ZonedDateTime.now(zone);

        // Calculate years between dates
        long years = ChronoUnit.YEARS.between(birthDay,zdtNow);

        // Calculate months part
        ZonedDateTime forward = birthDay.plusYears(years);
        long months = ChronoUnit.MONTHS.between(forward,zdtNow);

        // Calculate days part
        forward = forward.plusMonths(months);
        long days = ChronoUnit.DAYS.between(forward,zdtNow);

        System.out.println(years + " years " + months + " months " + days + " days");
    }
}

输出：

23 years 11 months 17 days

我在您的问题中看到您尝试了类似Date = new Date()的操作。请注意，java.util.Date类已经过时了。我建议您停止使用过时且容易出错的java.util日期时间API，并切换到modern date-time API。