I'm trying to set up calendar events in macOS Sierra's Calendar that repeat every 2,551,440 seconds (which happens to be the synodic period of the Moon).
Ultimately, I want a calendar that provides the Moon rise and set times for my location, and it also needs to list the Lunar phase (e.g. Full Moon, New Moon, etc.). I have found plenty of examples on the Internet where people have manually created the events, but that's incredibly tedious (one event per day for years!), and it's based on different time zones (and so are of no use to me).
I have seen from the ICS specifications that the file format itself supports events that recur every x seconds. I then exported an event as an ICS file, and then edited the ICS file in TextEdit, but I must've got the code wrong, as it didn't re-import into macOS Calendar with the correct repeat interval. Instead, it imported a single event with no repetition.
Can someone please explain how to go about doing this?
I found the RRULE Generator, but that only supports hourly intervals, not seconds, and so is not precise enough for my needs.
I considered running a bash script to generate the event (which would run as a cron job every 2,551,440 seconds), but that would only give a month's notice. I'd prefer to have it set up indefinitely.
Another option may be to write a script in Python to create individual ICS event files; this would also be tedious...
I understand that this can't be done in Calendar directly; the solution will most likely be manually editing each ICS file to set up the recurrence correctly, and then importing them into Calendar... I just don't know how...
Thanks in advance for any thoughts.