Converting Dates from CCYYMMDD to CCYYDDD !!!

Converting Dates from CCYYMMDD to CCYYDDD!

We were recently asked to convert from CCYYMMDD dates to CCYYDDD date, and I came up with the following:

:comment Step One: convert date to have a century field and a begining of year date
in datefile
def boy,1,4,double
def century,1,4,double
item boy,date,ccyymmdd
item mydate,date,ccyymmdd
ext mydate
ext boy=$truncate(a / 10000) * 10000 + 0101
ext century=$truncate(a / 10000)
out workfile,link
xeq

Step Two: Format and determine number of days since Beginning of Year.
in workfile
def newdate,1,4,double
ext mydate
ext boy
ext century
ext diff=$days(mydate) - $days(boy) + 1
ext newdate=(century * 1000) + ($days(a) - $days(boy) + 1)
out convert,link
xeq

You can see the results below including the starting date, you don't need to include all the fields in the result file:

>IN convert (0) >OUT $NULL (0)
MYDATE          = 20141213       BOY             = 20140101
CENTURY         = 2014           DIFF            = 347
NEWDATE         = 2014347

>IN convert (1) >OUT $NULL (1)
MYDATE          = 20131221       BOY             = 20130101
CENTURY         = 2013           DIFF            = 355
NEWDATE         = 2013355

>IN convert (2) >OUT $NULL (2)
MYDATE          = 20150321       BOY             = 20150101
CENTURY         = 2015           DIFF            = 80
NEWDATE         = 2015080

>IN convert (3) >OUT $NULL (3)
MYDATE          = 20100904       BOY             = 20100101
CENTURY         = 2010           DIFF            = 247
NEWDATE         = 2010247

IN=4, OUT=4. CPU-Sec=1. Wall-Sec=1.

The basis of this was to take the current date and make up a second date and make up the Beginning Of Year date, and use $days and get the difference in days between the current date and the Beginning of Year. Thus the "Julian Date" or ccyyDDD, is the current century * 1000, plus the number of days difference (+1) from the beginning of the year.