Detailed Instructions

First create a new empty calendar. Then make sure to import whatever you are importing into that calendar. 

The import process may also give you an option to create a new calendar while importing. This works too. It doesn't matter which way you do it - as long as you keep each calendar's data in its own calendar.  

Here's a short video showing creating a new calendar on an iPad.  Watch the bottom left corner for the clicks:

https://www.youtube.com/watch?v=SR8ok9EZ5K0

Here's the Google instructions page:

https://support.google.com/calendar/answer/37095?hl=en

You can import to as many calendars as you like. You can edit the calendars because they are yours. If you make a mistakes, you can just re-import them into a new calendar.

Once you get a few different calendars set up you can watch this video on how to see them all at once (it's for Android but similar to iPhone):  

https://www.youtube.com/watch?v=Y_VqzxVqO44

How to Subscribe to the Large 2024 and before Transit Calendar

Here's the entire current 2024 calendar and before file going back to 2010 (thousands of transits, about 12mb):

https://calendar.google.com/calendar/ical/qf8vj00k7jm0o7kmpu4e6b06dk%40group.calendar.google.com/public/basic.ics

You can save the calendar as a local file on your device, and import from there. 

This will allow the device to adjust to your timezone. Logging into Google and subscribing from there has the same effect.

Note: This large calendar going back to 2010 has all the Moon and Moon void-of-course aspects. Best to do this from a pc or newer phone/tablet/device because of the large file size. Some browsers, calendar apps, etc. might be overwhelmed with so many aspect "events".

If you are a bit Google-savvy, you can continue to let Google host the calendar in the cloud for you:

1) Login to your Gmail or Google Account.  https://myaccount.google.com/

2) Click the following link after logging in:

https://calendar.google.com/calendar/render?cid=qf8vj00k7jm0o7kmpu4e6b06dk@group.calendar.google.com

3) Click the "Add Calendar" button.

You can also choose Import from the sidebar and give it this ID: qf8vj00k7jm0o7kmpu4e6b06dk@group.calendar.google.com

Tips:

For more control over the calendar: create a new calendar in your Calendar area. Then import the calendar ical/ics formatted file into that calendar.

The ical/ics method works well with Apple products and many other calendar programs.

For reference: Large 2024 and before Calendar ID:   qf8vj00k7jm0o7kmpu4e6b06dk@group.calendar.google.com