# Re: st: From Weekly Data to Monthly Data

 From Timothy.Mak@iop.kcl.ac.uk To statalist@hsphsun2.harvard.edu Subject Re: st: From Weekly Data to Monthly Data Date Mon, 24 Oct 2005 15:05:03 +0100

```perhaps it's easiest if you use a calendar for those years, and work out
exactly which month that week falls into. If a week falls 3 days into Jan
and 4 days into Feb, say, then you can group it into February. In this way
some months will be based on 5 weeks and others 4, but i guess that's the
best you can do.

Tim

"Thomas Speidel" <thomassp@cancerboard.ab.ca>
Sent by: owner-statalist@hsphsun2.harvard.edu
24/10/2005 14:50
statalist@hsphsun2.harvard.edu

To
<statalist@hsphsun2.harvard.edu>
cc

Subject
st: From Weekly Data to Monthly Data

I have a dataset containing yearly and weekly data starting from week 1
1999 (i.e. week of Jan 1, 1999) to week 53.  This is repeated from year
1999 to year 2004.  I am trying to convert this data to monthly data,
containing the total no. of units for each month of each year.  The
problem is all months (except some Februarys) contain a little more than
4 weeks, and so computing the total for each month is not
straight-forward. I guess any solution will have to include some error,
which is fine.

Any ideas? Thanks for any suggestions.
Thomas

The following is a sample of my data:

year             weeks           units
1999             1               600
1999             2               597
1999             3               588
1999             4               562
1999             5               558
1999             6               544
1999             7               531
1999             8               533
1999             9               541
1999             10              534
1999             11              526
1999             12              502
1999             13              503
1999             14              498
1999             15              499
1999             16              488
1999             17              494
1999             18              505
1999             19              507
1999             20              518
1999             21              534
1999             22              555
1999             23              547
1999             24              566
1999             25              563
1999             26              580
1999             27              570
1999             28              583
1999             29              605
1999             30              602
1999             31              616
1999             32              627
1999             33              645
1999             34              668
1999             35              671
1999             36              690
1999             37              703
1999             38              720
1999             39              730
1999             40              741
1999             41              721
1999             42              750
1999             43              761
1999             44              763
1999             45              774
1999             46              797
1999             47              795
1999             48              796
1999             49              813
1999             50              815
1999             51              797
1999             52              771
1999             53              .
2000             1               786
...
2004  53    .

This e-mail and any attachments may contain confidential and
privileged information. If you are not the intended recipient,
please notify the sender immediately by return e-mail, delete this
e-mail and destroy any copies. Any dissemination or use of this
information by a person other than the intended recipient is
unauthorized and may be illegal.

*
*   For searches and help try:
*   http://www.stata.com/support/faqs/res/findit.html
*   http://www.stata.com/support/statalist/faq
*   http://www.ats.ucla.edu/stat/stata/

*
*   For searches and help try:
*   http://www.stata.com/support/faqs/res/findit.html
*   http://www.stata.com/support/statalist/faq
*   http://www.ats.ucla.edu/stat/stata/
```