Help with creating a formula to convert a Production date to Standard or vice versa

[Zoso4]

Hello! I'm new here so bare with me.

I recently started working for a company that uses a production date along with the normal date system. It is easy to understand while viewing the calendar but it basically works by week numbers, starting from the beginning of the year, then the individual day numbers Monday equaling 1 through Sunday equaling 7 after that. So at Jan. First of this year it would have been
Tues. 1/1/13 = 1.2
Wed. 1/2/13 = 1.3
Thurs. 1/3/13 = 1.4
Friday 1/4/13 = 1.5
Sat 1/5/13 = 1.6
Sun 1/6/13 = 1.7
Mon 1/7/13 = 2.1
Tues 1/8/13 = 2.2
and so on until the end of the calender year. I work in a lot of different spreadsheets where some people have dated things with standard date and others with the production date.

I have been looking for a way to convert one to the other or vice versa but Have had no luck so far =[
Anyone out there had experience with this type of dating system before or know of a formula/macro to convert to it?

 

[RonB1111]

With a standard date in A1, this formula will convert it to your production date:
=WEEKNUM(A1,2)&"."&WEEKDAY(A1,2)

With a production date in A1, this formula will convert it to a standard date (change the 2 instances of year 2013 to the year you're looking for):
=DATE(2011,1,RIGHT(A2,1)-WEEKDAY(DATE(2011,1,1),2)+LEFT(A2,FIND(".",A2-1))*7-6)

 

[Zoso4]

Wow that seemed so simple, I must have been over thinking it. Thank you so Much!!!

 

[RonB1111]

You're welcome. Thank you for providing feedback.