APLawrence.com -  Resources for Unix and Linux Systems, Bloggers and the self-employed

Early reminders for first Monday of month events

© October 2012 Anthony Lawrence


I kept forgetting to send our club meeting notices to the newsletter. Google Calendar couldn't help me, so I wrote this script.

I help run a monthly Computer Club meeting in our community. The club actually meets twice per month, once for a general meeting and once to offer troubleshooting services to members of the community.

I keep forgetting to put meeting notices in our community newsletter.

That sounds like a job for a calendar program, doesn't it? Yeah, that's what I thought too, so I fired up Google Calendar and added the two dates for the first Monday and the first Wednesday of every month. So far, so good and now all I had to do was to tell it to remind me at an appropriate time.

Google Calendars reminder

Unfortunately, I ran into an immediate problem. I need to get notices to the newsletter editor very early. If I want something to be in the December newsletter, I need to send it in before the first of November. Google Calendar won't let you set a reminder more than one month earlier than an event. If I try to set it for 5 weeks or 32 days, it won't allow that. That's dumb, but there it is: Google doesn't think you'd ever need more than 4 weeks advance notice for anything.

Perl to the rescue

So, I turned to Perl.

There are many ways to approach this in Perl. You could take a brute force approach, setting the date to December 1st, testing to see if that is a Monday and incrementing to December 2d and beyond if it is not. That's actually not such a terrible way to do it as the date we want has to be before the 8th, so there cannot be many iterations.

use Time::Local;

if ($month > 11) {
  $month=0; $year++;
$dow=(localtime $nextmonth)[6];
while ($dow != 1) {
 $nextmonth+=24 * 60 * 60;
 $dow=(localtime $nextmonth)[6];

print scalar localtime $nextmonth, "\n";;

If you ran that on the 28th of each month, you'd have the first Monday of the 2d month following. Add some code to send email and you are done.


I decided to use Date::Calc instead. It's probably no faster (it might even be slower) and it very likely uses a brute force approach itself, but it has a lot of useful functions (68, in fact) beyond just what we need to do here.

Installing Date::Calc is, however, a somewhat lengthy procedure. It's a lot of code with a whole army of dependencies and it will keep CPAN busy for quite a little while. It will be worth it, though, as our code becomes as simple as:

  ($year,$month,$day) = Today();
  ($year,$month,$day) = Add_Delta_YMD($year,$month,$day, 0,2,0);

We just need to wrap that up in some formatting and we're ready to put it in crontab:

10      6       28      *       *       /mybin/remindme 2>&1 > /dev/null

I'll run it on the 28th of each month and it will send me a reminder email that is ready for any last many editing before being forwarded along to the newsletter.

# "remindme" Tony Lawrence October 2012
# I'm going to run this on the 28th of the month
# I want to know the first Monday and First Wednesday of TWO months ahead
use Date::Calc qw( Today Date_to_Days Add_Delta_YMD Decode_Date_US Nth_Weekday_of_Month_Year );
@months=("January","February", "March", "April", "May", "June", "July", "August", "September", "October", "November","December");

  ($year,$month,$day) = Today();
  ($year,$month,$day) = Add_Delta_YMD($year,$month,$day, 0,2,0);
  $monday=~ s/$year$month//;
  $wednesday=~ s/$year$month//;

open(SENT,"|/opt/kerio/mailserver/sendmail tony\@aplawrence.com");
print SENT <<EOF;
Mime-Version: 1.0
Content-Type: text/html
Content-Transfer-Encoding: 8BIT
From: tony\@aplawrence.com
Subject: Computer club schedule for $months[$month-1] $year

<h2>Oak Point Computer Club $months[$month-1] $year</h2>

<p>The Oak Point Computer Club meets on the first Monday and the first Wednesday of every month.</p>

<li>The Monday $months[$month-1] $day[$monday-1] meeting is at 2:00 PM in the Back Ballroom.</li>

<li>The Wednesday $months[$month-1] $day[$wednesday-1] meeting is at 5:00 PM in the Back Ballroom.</li>

<p>Wednesday is Troubleshooting.  Bring us your problems and questions and we will try to help. First come, first served.</p>

<p>Monday is usually a lecture or informal discussion on some subject.</p>
<p><b>Not just for computer geeks!</b></p>
<p>All Oak Point homeowners are welcome; there are no dues or charges of any kind.</p>
exit 0;

This is the result:

Early reminder email

That should help me get my notices to the newsletter on time.

Got something to add? Send me email.

(OLDER)    <- More Stuff -> (NEWER)    (NEWEST)   

Printer Friendly Version

-> Early reminders for first Monday of month events

Inexpensive and informative Apple related e-books:

Photos for Mac: A Take Control Crash Course

Digital Sharing Crash Course

Take Control of the Mac Command Line with Terminal, Second Edition

Take Control of Preview

Take Control of Upgrading to El Capitan

More Articles by © Anthony Lawrence

Printer Friendly Version

Have you tried Searching this site?

This is a Unix/Linux resource website. It contains technical articles about Unix, Linux and general computing related subjects, opinion, news, help files, how-to's, tutorials and more.

Contact us

Printer Friendly Version

Tough times never last, but tough people do. (Robert H. Schuller)

Linux posts

Troubleshooting posts

This post tagged:




Unix/Linux Consultants

Skills Tests

Unix/Linux Book Reviews

My Unix/Linux Troubleshooting Book

This site runs on Linode