@Override
  public String toString() {
    return localDate.format(PRINT_FORMATTER);
  }
This is the internal type for Date. The full qualified input format of Date
is "uuuu-MM-dd". For example: "2021-02-11".
<table border="1">
    <caption></caption>
<tr>
<th>Field</th>
<th>Format</th>
<th>Description</th>
</tr>
<tr>
<td>Year</td>
<td>uuuu</td>
<td>The proleptic year, such as 2012. This represents the concept of the
year, counting sequentially and using negative numbers.</td>
</tr>
<tr>
<td>Month of Year</td>
<td>MM</td>
<td>The month-of-year, such as March. This represents the concept of the
month within the year. In the default ISO calendar system, this has values
from January (1) to December (12).</td>
</tr>
<tr>
<td>Day of Month</td>
<td>dd</td>
<td>This represents the concept of the day within the month. In the default
ISO calendar system, this has values from 1 to 31 in most months.</td>
</tr>
</table>
<p>
The {@link ChronoField#YEAR} and "uuuu" format string indicate the year. This
is not to be confused with the more common "yyyy" which standard for
"year-of-era" in Java. One important difference is that "year" includes
negative numbers whereas the "year-of-era" value should typically always be
positive.
</p>

@see java.time.temporal.ChronoField#YEAR
@see java.time.temporal.ChronoField#YEAR_OF_ERA
common/src/java/org/apache/hadoop/hive/common/type/Date.java