Day of the Week
<p>Given a date, return the corresponding day of the week for that date.</p>

<p>The input is given as three integers representing the <code>day</code>, <code>month</code> and <code>year</code> respectively.</p>

<p>Return the answer as one of the following values&nbsp;<code>{&quot;Sunday&quot;, &quot;Monday&quot;, &quot;Tuesday&quot;, &quot;Wednesday&quot;, &quot;Thursday&quot;, &quot;Friday&quot;, &quot;Saturday&quot;}</code>.</p>

<p>&nbsp;</p>
<p><strong class="example">Example 1:</strong></p>

<pre>
<strong>Input:</strong> day = 31, month = 8, year = 2019
<strong>Output:</strong> &quot;Saturday&quot;
</pre>

<p><strong class="example">Example 2:</strong></p>

<pre>
<strong>Input:</strong> day = 18, month = 7, year = 1999
<strong>Output:</strong> &quot;Sunday&quot;
</pre>

<p><strong class="example">Example 3:</strong></p>

<pre>
<strong>Input:</strong> day = 15, month = 8, year = 1993
<strong>Output:</strong> &quot;Sunday&quot;
</pre>

<p>&nbsp;</p>
<p><strong>Constraints:</strong></p>

<ul>
	<li>The given dates are valid dates between the years <code>1971</code> and <code>2100</code>.</li>
</ul>
Math
import java.util.Calendar;

class Solution {
    private static final String[] WEEK
        = {"Sunday", "Monday", "Tuesday", "Wednesday", "Thursday", "Friday", "Saturday"};

    public static String dayOfTheWeek(int day, int month, int year) {
        Calendar calendar = Calendar.getInstance();
        calendar.set(year, month - 1, day);
        return WEEK[calendar.get(Calendar.DAY_OF_WEEK) - 1];
    }
}