I'm not super sure about it being in the filename, if only because my understanding is that some of the lakes use it for partitioning and other metadata (metameta-data?).

Imo range is probably the most useful statistic in a folder/file name anyways for partitioning purposes. My vote would be for `^` as the range separator to minimize risk of collision and confusion. i.e. `timestamp=2025-03-27T00:00:00-0800^2025-03-30-0700` or `hour=0^12`,`hour=12^24`. `^` is valid across all systems, and I'd be very surprised if it was commonly used as a property/column name. Only collision I can think of is that its start-of-line in regex

Too late to edit buuut

There's a standard! (for time intervals, and I could see it working here)[0]

> Section 3.2.6 of ISO 8601-1:2019 notes that "A solidus may be replaced by a double hyphen ["--"] by mutual agreement of the communicating partners",

So forget what I said; why exacerbate the standards problem?[1]

[0]https://en.wikipedia.org/wiki/ISO_8601#Time_intervals [1]https://xkcd.com/927/