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.