Returning the week number for a week that starts on Saturday in the Australian Calender

I am using

=(WEEKNUM(C11,2)+26)

to try and return a week number where in C11 is the date "30/06/12" but its returning "53". Does anyone know why and how I can get it to return "1" and then return "1" for subsequent Saturdays eg this year 29/06/13 is week 1

Thanks in advance

John

I have attached an example. I want the user to be able to put in the date in the top (C1) that will be the first date of the new calendar year. This will then update the week number to the right week. Because the Australian calendar is between June - June and will differ the start date year to year so 2012 was 30/06/12, 2013 is 29/06/12. If I change the date in C1 to 29/06/13 all is good except the week of the 1/1/13 because the is where the formula changes from ="Week "&(WEEKNUM(C186,16)-26) to ="Week "&(WEEKNUM(C186,16)+26) otherwise it returns Week -25 but like this it returns Week 79.

Hope this makes sense - I have highlighted the cells in the attached

Book1.xlsx

no. I think im just going to manually enter the weeks, thanks anyway.

Thanks - I got it working with:

="Week "&INT((C1-C$1)/7)+1