Support DateTimeOffset type

[drhumlen]

Description

We use DateTimeOffset for everything instead of regular DateTime since it maintains time zone information. Right now we have to |> List.map (fun datetimeoffset -> datetimeoffset.UtcDateTime) every time we chart up something.

Would it be possible to support DateTimeOffset directly?

[kMutagene]

Hi @drhumlen,

The problem here is DateTimeOffset not implementing IConvertible while DateTime does. For me it seems like we would not really have much of a choice here other than implementing overloads for every single chart function on DateTimeOffset for that to work, which seems quite overkill for a use case that can be solved with a single mapping/conversion step. Implementing IConvertible for DateTimeOffset also seems to be not that trivial and might also be overkill on your side, so i am afraid I do not have any good idea to tackle this from our side atm. There might be a solution coming up though, depending on when and if erased union types become a thing in F#.

[drhumlen]

Aha. That makes sense. Yeah implementing overloads for every method seems like tedious work when everything else works fine with just IConvertible. I guess the best workaround for now is for us to make some helpers that converts a list of DateTimeOffset to DateTime.

[kMutagene]

Cloosing for now, might be revisited when erased unions are a thing in F# so we could use things like (IConvertible|DateTimeOffset|SomeOtherType) as input