Function for day of the year

How do I write a function that responds the days of the year when given a certain date? For example, January 7th, 2017 would respond 7 as that is the 7th day of the year. (This is also accounting for leap years.)

Answer 1

[per isakson]

Introduced in R2014b

>> day( datetime('07-Jan-2017', 'InputFormat', 'dd-MMM-yyyy' ), 'dayofyear' )
ans =
     7

"accounting for leap years" If not, shame on The MathWorks!

>> day( datetime('01-Mar-2017', 'InputFormat', 'dd-MMM-yyyy' ), 'dayofyear' )
ans =
    60
>> day( datetime('01-Mar-2016', 'InputFormat', 'dd-MMM-yyyy' ), 'dayofyear' )
ans =
    61