Stata The Stata listserver
[Date Prev][Date Next][Thread Prev][Thread Next][Date index][Thread index]

st: Seasons from Dates

From   "Thomas Speidel" <>
To   <>
Subject   st: Seasons from Dates
Date   Mon, 28 Nov 2005 10:19:48 -0700

Dear Statalisters:

I am attempting to create a "season" variable based on a date variable.
The solstice start dates are Dec-21, Mar-21, Jun-21 and Sep-22 for
Winter(1), Spring(2), Summer(3) and Autumn(4) respectively.  I have
tried to accomplish this using a rather long series of logical operators
such as:

gen month=month(date)
gen day=day(date)
gen season=1 if (month>=12 & day>=21) | (month>=1 & (month<=3 & day<20))


However, this code is not correct as it excludes all days>=20.
Rather than adding more logical operators to condition upon the dates, I
was wondering if anyone has a suggestion for a cleaner, more elegant


Thomas Speidel
Statistical Associate
Clinical Trials Unit
Tom Baker Cancer Centre
1331 - 29th Street N.W.
Calgary, AB, T2N 4N4

Tel. (403) 521-3370

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:

© Copyright 1996–2017 StataCorp LLC   |   Terms of use   |   Privacy   |   Contact us   |   What's new   |   Site index