Don't think there's an exposed impl, but here you go:
proc julian*(year, month, day: int): int =
let a = (14 - month) div 12 # See calendar FAQ$2.16.1
let y = year + 4800 - a
let m = month + 12 * a - 3
(day + (153 * m + 2) div 5 + y * 365 +
y div 4 - y
Sure but is there an exposed implementation or would I be rolling my own?
Or you can simply calculate the difference in their Julian day numbers.
`std/times` seems to have
[toEpochDay](https://github.com/nim-lang/Nim/blob/e49d52eb6174b2721293968e7811928c303c3776/lib/pure/times.nim#L461)
and `fromEpochDay` but they're not exported. It would be useful if they were!
