To compact the output even further, there could be a Boolean configuration setting for each compact date range format to optionally remove the year values (and any preceding whitespace and/or single quote if a two digit year) from the final string, if both the start and end years are the current year.
So for example, outputs like "12th - 14th February 2023" or "12-14 Feb '23" become simply "12th - 14th February" or "12-14 Feb" while it is 2023.
A new checkbox field in the configuration of each compact date range format to turn this functionality on or off, defaulting to off.
I've attached a patch that works for me. If the module maintainer is happy, I can commit the changes to the module dev branch?
Needs review
2.0
Code
Interesting suggestion. This is going to need test coverage before anything else.
One thing to bear in mind: introducing the notion of "current year" to the display makes this time-sensitive. That has implications for cacheability. For example, if we reduce "12th - 14th February 2024" to "12th - 14th February", the output is now only valid till the end of 2024.