Well yes, technically you're correct. Nothing prevent you from calling it only once a day instead once a minute. As long as the URL is correct.

(On a popular site this might however cause problems, if too large amount of notifications get piled up to the notifications queue during the day.)

Out of curiosity: why do you want to send notifications only once a day?

No, you should create a cronjob that does a wget on http://www.myurl.com/cron/minute/ once per minute (if you do it just once per day the notifications will pile up and only be sent once per day!).

Some info about cron and Elgg's cronjobs: http://learn.elgg.org/en/1.9/admin/cron.html.

Some plugins will register for Elgg's cron plugin hooks for execution of functions on different intervalls. For example the bundled logrotate and garbagecollector plugins will clean up the database once per month (intervall set by default) or whatever intervall you set in their plugin settings. So, you should create cronjobs that do wgets on the corresponding cron urls at least for these intervalls that are in use by the installed plugins.

You can use my croncheck plugin (https://community.elgg.org/plugins/1864611/1.8.0/elgg-1819-croncheck) to see which cron intervalls are in use by your plugins. The plugin adds this info to the default croncheck page in the admin section of your Elgg site where it is only visible when the cronjobs have run last.

Thanks a lot.

@Juho : in fact, I would like to find a plugin that send on the same page all the followed activities of a day (with the subject only). I don't know if it exists.

And my provider lets me run only ten automatic tasks. I have a shared server. So I choose to run only one by day. Perhaps, I have to increase it to 6 tasks every 2 hours from 8 am to 8 pm.

@iionly : I use already your great plugin.

Thanks.