Bit of a cheat here… To my knowledge there isn’t a specific way to sort your collection in the way you want to from right to left, but I’ve tested this out and it seems to work, if I’ve understood you correctly
If you give the Collection List a Class, I went for Right-Collection-List…
Go to styles and set it to Flex, horizontal (in below screen shot). When using Flex you will see a check box option just underneath that says Reverse Layout, click this and you will see the Calendar entries now run Right To Left.
You may also want to add some sort filters to the collection, such as ‘Oldest to Newest’ for the Start Date/Time field in your collection. This will just protect the order in future to display by dates and not when they were added to the collection.
I can see your calendar appears in numerous places across the site, this should work in other places to, you may just need to also check the Wrap Children box on Flex settings when you need multiple lines of calendar entries.
Let me know how you get on??