from the cli
$ todo -r
4. Use the -r option to enter a recurrent task. You will be prompted to enter all fields, separated by semi-colons. Fields are tag, date, text, number of times the event repeats, and length of time between the events (days, weeks, months).
cal will be shown on the screen before the prompt
Example:
admin ; fri ; run the backup scripts; 4; week
The fields get listed in the way you shall enter them, before you
are prompted:
<tag> ; <due date> ; <message> ; <repeats> ; <cycle>
So it is easy to handle, just try.