An interval type

[ariebovenberg]

Something that's quite common in datetime libraries is an 'interval' type.

It's not the question whether such a thing could be implemented, but whether it is possible to define the 'just right' abstraction that supports the common use cases without being overly complex.

Questions that come to mind:

• are intervals always closed-open, or are other variants possible?
• Can intervals only exist of aware types?

[simon04]

are intervals always closed-open, or are other variants possible?

Citing from https://www.reddit.com/r/ISO8601/comments/1beahww/intervals/:

ISO 8601-1:2019 states

3.1.1.6 time interval
part of the time axis limited by two instants and, unless otherwise stated, the limiting instants themselves

so it's inclusive-inclusive by default, but it's probably better to specify it yourself because it's not reasonable for someone to expect 12:00/13:00 to be 61 minutes long