I have many transactions with a date time value and I want to determine within what week of the year that date time value falls. For example there are 52 weeks in a year and week 1 is 1/1/08 to 1/7/08 and week 2 is 1/8/08 to 1/14/08 and week 52 is 12/25/08 to 12/31/08 etc... I will then graph the results for the year; thus, I will have 52 plots on a graph which represents all my data for the full year of transactions. thanks for your time!

This message has been edited. Last edited by: Kerry,

DEFINE FILE CAR
DATE1/A10 WITH COUNTRY= TODAY(DATE);
DATE2/HMDYYs = HINPUT(14, DATE1, 8, 'HMDYYs');
WEEK/I2 = HPART(DATE2, 'WEEK', 'I2');
END
-*
TABLE FILE CAR
SUM
MAX.DATE1
MAX.DATE2
MAX.WEEK
END

Unfortunately, this does not give the week number that Denny99 is looking for. The WEEK component of the Date-Time column is a Saturday-Friday week number (the range of which you can modify using the WEEKFIRST setting), while Denny99 is looking for a week number starting on the first day of the year, which may not be a Monday so there might be a discrepancy between the two.

2009:

 m  t  w  t  f  s  s  |  m  t  w  t  f  s  s
-- -- -- -- -- -- --  | -- -- -- -- -- -- --
          1  2  3  4  |  5  6  7  8  9 10 11
          0  0  1  1  |  1  1  1  1  1  2  2 <== week component of date-time field
          1  1  1  1  |  1  1  1  2  2  2  2 <== week number

I think you have to do this using the day-of-year component and divide by 7.

DEFINE FILE CAR
DATE1/A8 WITH COUNTRY= '20080108';
DATE2/HMDYYS = HINPUT(14, DATE1, 8, 'HMDYYS');
WEEK/I2 = HPART(DATE2, 'WEEK', 'I2');
DOY/I3 = HPART(DATE2, 'DAY-OF-YEAR', 'I3');
WEEKB/I2 = IF IMOD(DOY, 7, 'I3') EQ 0 THEN (DOY / 7) ELSE (DOY / 7) + 1;
END

TABLE FILE CAR
SUM
MAX.DATE1
MAX.DATE2
MAX.WEEK
MAX.DOY
MAX.WEEKB
END

Probably doesn't matter much, but the last day of the year is going to give you a 53rd plot point because a year is 52 weeks and 1 (or 2) days. Francis' code, for most purposes, solves the problem as it uses modular division but that still doesn't resolve the issue of the extra day(s).

As the length of a year is virtually constant, give or take 1 second from year to year, the calc of weeks 1 to 52/53 is the best way.

All depends on what Denny99 wants in his graph.

... and don't forget that there are differences between week numbers depending upon what standard you need to use - MS or ISO 8601.

ISO 8601 begins numbering weeks for the first week to contain a Thursday (other factors as well but this is the main one) whereas MS (as usual) decide that week number one is the first whole week within a year.

Find out which convention that you are required to use and code accordingly.

T

Thinking of week numbers and things like that I would recommend this article.

The French Revolutionairy Calendar

It's a funny idea ....

Sansculottides
LOL
what a leap year tradition!
except the french seem to have it for 5 days instead of 1
say,,summit is about 5 days long...
hmmmm

Yes

I tell my boss I go to Summit this afternoon and I will be back tomorrow......