为什么java.util.Date将Year表示为“year-1900”？

* In all methods of class <code>Date</code> that accept or return
 * year,month,date,hours,minutes,and seconds values,the
 * following representations are used:
 * <ul>
 * <li>A year <i>y</i> is represented by the integer
 *     <i>y</i><code>-1900</code>.

当然,在Java 1.1中,不推荐使用getYear()方法等来支持java.util.Calendar,它仍然有这个奇怪的弃用说明：

int    getYear() 
    Deprecated. As of JDK version 1.1,replaced by Calendar.get(Calendar.YEAR) - 1900.

 setYear(int year) 
      Deprecated. As of JDK version 1.1,replaced by Calendar.set(Calendar.YEAR,year + 1900).

当然,Month是基于0但我们都知道(尽管你认为他们已经从日历中删除了这个问题 – 他们没有)：

* <li>A month is represented by an integer from 0 to 11; 0 is January,*     1 is February,and so forth; thus 11 is December.

我确实检查了以下问题：

Why does Java’s Date.getYear() return 111 instead of 2011?

Why is the Java date API (java.util.Date,.Calendar) such a mess?

我的问题是：

> java.util.Date的原始创建者可能希望通过从中减去1900来存储“年份”的数据？特别是如果它基本上存储为长.

因此：

private transient long fastTime;

@Deprecated
public int getYear() {
    return normalize().getYear() - 1900;
} 

@Deprecated
public void setYear(int year) {
    getCalendarDate().setNormalizedYear(year + 1900);
}

private final BaseCalendar.Date getCalendarDate() {
    if (cdate == null) {
        BaseCalendar cal = getCalendarSystem(fastTime);
    ....

>为什么选择1900？