Rails whenever gem: each month on the 20th

I searched all over the internet for this, and the documentation isn't really talking about monthly jobs in specific. So I was hoping that someone here could tell me how to do this.

I've installed the whenever gem and all I need to know is开发者_如何学Go the right syntax for this:

every :month, :on => '20th', :at => '02:00' do
  runner "Mailer.send_friend_sheet"
end

Hope someone can point me in the right direction..

Thanks!

---

You can use raw cron syntax as well if you cant figure out how to use with ruby syntax.

What you want will look like:

every '0 2 20 * *' do
  command "echo 'you can use raw cron syntax too'"
end

Here is a quick cheatsheet for how to use cron syntax

*     *     *   *    *        command to be executed
-     -     -   -    -
|     |     |   |    |
|     |     |   |    +----- day of week (0 - 6) (Sunday=0)
|     |     |   +------- month (1 - 12)
|     |     +--------- day of month (1 - 31)
|     +----------- hour (0 - 23)
+------------- min (0 - 59)

Shamelessly stolen from: http://adminschoice.com/crontab-quick-reference

---

If you want it more readable you can also just parse a date in text.

every 1.month, :at => 'January 20th 2:00am' do
  runner "Mailer.send_friend_sheet"
end

This will generate 0 2 20 * * as well.

---

Whenever doesn't support an :on option as far as I am aware, but you should be able to do

every '0 2 20 * *' do
  runner "Mailer.send_friend_sheet"
end

The '0 2 20 * *' is simply the relevant cron syntax - see http://www.manpagez.com/man/5/crontab/

---

Even better:

every 1.month, at: 'start of the month at 2am' do
  runner "Mailer.send_friend_sheet"
end