@bamajr Thats simple. Everyone may not want to set corntab, so, it is disabled by default.
You can clearly see it is advised to put following code in official documentation of EE https://easyengine.io/docs/lets-encrypt
0 12 * * * ee site update --le=renew --all 2> /dev/null
It is slightly different from the code I advised before but it doesn't matter because the five digits (in this case 0 12 * * *) before the actual command, define the date and frequency (monthly, daily) at which the command is supposed to run.
It's format is
* * * * *
| | | | |
| | | | +-- Year (range: 1900-3000)
| | | +------ Month of the Year (range: 1-12)
| | +-------- Day of the Month (range: 1-31)
| +---------- Hour (range: 0-23)
+------------ Minute (range: 0-59)
For example If you set it as
* * * * * , the command will run each minute (not advised).
By default it is set as
0 0 * * 0, in which the last digit which represent year is set to 0, but it should have value 1900-3000; setting it to 0 means it will never run and in your case you should left it * because you can't run command yearly as letsencrypt license expires in 3 months.
The first two digits are both 0 which represent hour and minute. So, if other fields are left as * and first two digit as 0
(0 0 * * *), the command will run every day at 00:00 (Midnight) and if you set it as
(0 12 * * *), as defined in official documentation, it will run everyday at 12:00 which is not bad but may consume a lot of resource and we don't need it as letsencrypt certificate expires only in 3 months. So we are modifying the code and set the third digit which defines month to 1 (
0 0 1 * *) so that it runs once in a month; 1st of each month at midnight to be exact.
Hope it helps.