Given a string date representing a Gregorian calendar date formatted as YYYY-MM-DD, return the day number of the year.
Example 1:
Input: date = "2019-01-09"
Output: 9
Explanation: Given date is the 9th day of the year in 2019.
Example 2:
Input: date = "2019-02-10"
Output: 41
Example 3:
Input: date = "2003-03-01"
Output: 60
Example 4:
Input: date = "2004-03-01"
Output: 61
Constraints:
- date.length == 10
- date[4] == date[7] == '-', and all other date[i]'s are digits
- date represents a calendar date between Jan 1st, 1900 and Dec 31, 2019.