Is there a way of adjusting WEEKNUMs to match a financial year?

Question

Hi
I am wondering if there is a way to have Numbers 09 adjust the WEEKNUMs so that they match the financial year, starting in the first week of April (UK). Given that I will have to do tax returns which match the financial year, it makes sense to match my accounts/Numbers files with the financial year.
Thanks
Nick

Answer 1

nick_harambee wrote:
I am wondering if there is a way to have Numbers 09 adjust the WEEKNUMs so that they match the financial year, starting in the first week of April (UK). Given that I will have to do tax returns which match the financial year, it makes sense to match my accounts/Numbers files with the financial year.
I guess the place to start here is 'Which numbering system do you want to modify for this?'
1) ISO Week: The International Organization for Standardization (ISO) ISO8601:2000 Standard
All weeks begin on a Monday. Week one starts on Monday of the first week of the calendar year with a Thursday.
2) (Not included as week starts on Sunday. Otherwise same as #3)
3) Excel(and Numbers) WEEKNUM function with an optional second argument of 2.
Week one begins on January 1st; week two begins on the following Monday.
4) Simple week numbering.
Week one begins on January 1st, week two begins on January 8th, and week 53 has only one or two days(for leap years).
For modified system 1 (ISO), replace "calendar year" with "financial year". For modified WEEKNUM and Simple Week Numbering systems, replace "January" with "April"
The nice thing about #4 is that it is "simple", and that simplicity extends to the ease of starting with any specific date. No correction factor is needed for the transition from one calendar year to the next.
The shifting start dates of Week 1 of #1 and of Week 2 of #3 add a complication, but if these can be determined, the rest of the year can easily be numbered using the same formula as #4.
Here are the three choices, with formulas below.
SWN
Start Date: April 1, constructed from A1.
Table 1::B2: =INT(DATEDIF(DATE($A$1,4,1),A, "D")/7)+1
(Results modeled on) WEEKNUM
Start Date: Monday preceeding April 2
Table 2::B2: =(DATE(Table 1 :: $A$1,4,1)-WEEKDAY(DATE(Table 1 :: $A$1,4,1),3))
Table 1::C2: =INT(DATEDIF(Table 2 :: $B$2,A, "D")/7)+1
(Modeled on) ISO
Start Date: Monday preceeding first Thursday in April
Table 2::B2: =IF(WEEKDAY(DATE(Table 1 :: $A$1,4,1),3)<4,(DATE(Table 1 :: $A$1,4,1)-WEEKDAY(DATE(Table 1 :: $A$1,4,1),3)),(DATE(Table 1 :: $A$1,4,1)+7-WEEKDAY(DATE(Table 1 :: $A$1,4,1),3)))
Table 1::D2: =IFERROR(INT(DATEDIF(Table 2 :: $C$2,A, "D")/7)+1,53)
Note: IFERROR traps the error that occurs when April 1 falls on a Friday, Saturday or Sunday, and assigns the days before the first Monday to Week 53. You may prefer to consider (and label) this Week 0. To do so, replace the 53 at the end of the formula with 0 (zero).
None of the formulas will give 'correct' results beyond one year after the starting date.
Regards,
Barry
EDIT: Noting your newest post, I think you may want to consider the Simple Week Numbering system, using a starting date of April 6.
Barry
Message was edited by: Barry