Documentation doesn't explain rounding functions accept a Period for `unit`

[yutannihilation]

Rounding functions (e.g. round_date()) accepts a Period object as unit argument, but this usage is not described in https://lubridate.tidyverse.org/reference/round_date.html. As unit accepts arbitrary strings that can be parsed into period, I guess passing Period objects is a valid usage. Is my understanding correct? If so, may I send a pull request to add some sentences about this to the doc?

library(lubridate, warn.conflicts = FALSE)

ceiling_date(today() + 1:7, days(3))
#> [1] "2020-11-07" "2020-11-07" "2020-11-07" "2020-11-10" "2020-11-10"
#> [6] "2020-11-10" "2020-11-13"

^{Created on 2020-11-03 by the reprex package (v0.3.0)}

[vspinu]

it's actually not an intended usage. It probably works because the unit is converted to character with your days(3) being converted into "3d 0H 0M 0S" which is parsed as 3 days. Better use "3d" as unit.

[vspinu]

I am closing this as I don't see a benefit in explicitly accepting periods as units. It would be confusing I think. Let me know if you have good use case to use periods as unit.

[yutannihilation]

Thanks for clarifying. I personally prefer using a typed object rather than a string because

1. we cannot know the string is in an acceptable format (though it's well-documented) without actually executing the function, and
2. the former feels slightly cleaner when I provide the unit programmatically (e.g. ceiling_date(x, days(i)) rather than ceiling_date(x, glue("{i}d"))).

But, probably both are just my preferences, so sticking with strings is fine to me :)

[vspinu]

I think your point 2 is a good one. Let's have it as an option.