<p>Given a string <code>date</code> representing a <a href="https://en.wikipedia.org/wiki/Gregorian_calendar" target="_blank">Gregorian calendar</a> date formatted as <code>YYYY-MM-DD</code>, return <em>the day number of the year</em>.</p> <p> </p> <p><strong>Example 1:</strong></p> <pre> <strong>Input:</strong> date = "2019-01-09" <strong>Output:</strong> 9 <strong>Explanation:</strong> Given date is the 9th day of the year in 2019. </pre> <p><strong>Example 2:</strong></p> <pre> <strong>Input:</strong> date = "2019-02-10" <strong>Output:</strong> 41 </pre> <p> </p> <p><strong>Constraints:</strong></p> <ul> <li><code>date.length == 10</code></li> <li><code>date[4] == date[7] == '-'</code>, and all other <code>date[i]</code>'s are digits</li> <li><code>date</code> represents a calendar date between Jan 1<sup>st</sup>, 1900 and Dec 31<sup>th</sup>, 2019.</li> </ul>