Google Calendar would let me do it every 16 weeks (112 days).
I use Windows 7.
Thanks.
There are various ways to do it but here is one application that is free for the purpose you describe.
You can calculate what those dates would be for x amount of years using this
and then use a couple of services (one for backup) that email the future:
If you access your Google Calendar from another interface like a phone app, you might be able to set the interval to 117 days, free from the arbitrary restrictions of the browser interface.
While I access Google Calendar through my computer’s web browser usually, I also have it available on my iPhone’s native calendar app. In that app, I can set a 117-day repeat interval.
Similar to Pasta’s suggestion, you can create it in Google calendar by importing the event if your phone app won’t let you. First, create an .ics file like below. Mine was created in Pacific Time Zone; if you aren’t sure how to adjust it for your zone, export your calendar and use the events there as an example.
Once you have the file, click Settings in Google Calendar. Select the Calendars tab, then click Import Calendar halfway down the page. Select your file and import.
BEGIN:VCALENDAR
PRODID:-//Google Inc//Google Calendar 70.9054//EN
VERSION:2.0
BEGIN:VEVENT
DTSTART;TZID=America/Los_Angeles:20170501T210000
DTEND;TZID=America/Los_Angeles:20170501T210000
RRULE:FREQ=DAILY;INTERVAL=117
DESCRIPTION:
LOCATION:
SUMMARY:Test reminder
BEGIN:VALARM
ACTION:EMAIL
DESCRIPTION:This is an event reminder
SUMMARY:Alarm notification
ATTENDEE:mailto:youremail@gmail.com
TRIGGER:-P0DT0H30M0S
END:VALARM
END:VEVENT
END:VCALENDAR
I’m not clear why this is a challenge. At those intervals you only have calculate a few dozen or so date separations to cover several decades. Just plug those intervals into google calendar with email notifications. It’s a half hours (or less) work at best.
Thanks everyone. Troutman’s solution worked fine.