# Re: st: dates and Stata

 From "Keith Dear (home)" To statalist@hsphsun2.harvard.edu Subject Re: st: dates and Stata Date Sat, 30 May 2009 13:00:12 +1000

```Maybe like this?

cap prog drop datecount
prog datecount
args month day start end
loc month=upper(substr("`month'",1,3))
scalar datecount=0
forval d=`=d(`start')'/`=d(`end')' {
loc thismonth=upper(ltrim("`:di %dm `d''"))
```
if "`month'"=="`thismonth'" & `day'==day(`d') scalar datecount=datecount+1
```   }
di as result datecount
end
```
```datecount sept 15 28jan1997 17sep2002
6
datecount Feb 2  28jan1997 17sep2002
6
datecount february 29 28jan1997 17sep2002
1

Regards,
kd

Olexandr O. Vasetsky wrote:
```
```Hi guys,

I am trying to calculate the number of certain day and month occurrences
between the two dates: e.g. calculating the number of September 15th's and
February 2nd's from 28-Jan-1997 to 17-Sept-2002.

any ideas will be appreciated

```
```
--
Dr Keith Dear
Senior Fellow
National Centre for Epidemiology and Population Health
ANU College of Medicine, Biology and Environment
Building 62, cnr Mills and Eggleston Roads
Australian National University
```
Canberra ACT 0200 Australia
```T: 02 6125 4865
F: 02 6125 0740
M: 0424 450 396
W: nceph.anu.edu.au/Staff_Students/staff_pages/dear.php

CRICOS provider #00120C
http://canberragliding.org/

*
*   For searches and help try:
*   http://www.stata.com/help.cgi?search
*   http://www.stata.com/support/statalist/faq
*   http://www.ats.ucla.edu/stat/stata/
```