[ARROW-15798] [R][C++] Discussion: Plans for date casting from int to support an origin option?

• Type: Improvement
• Status: Open
• Priority: Critical
• Resolution: Unresolved
• Component/s: C++, R
• External issue URL: https://github.com/apache/arrow/issues/31240
• Assignee: Unassigned
• Reporter: Dragoș Moldovan-Grünfeld
• Created: 28/Feb/22 14:33
• Updated: 11/Jan/23 11:39

Description

2 questions:

• plans to support an origin option for int -> date32 casting?
• plans to support double -> date32 casting?
  =======================
  Currently the casting from integer to date works, but assumes epoch (1970-01-01) as the origin. 

  > a <- Array$create(32L)
  > a$cast(date32())
  Array
  <date32[day]>
  [
    1970-02-02
  ]
  

Would it make sense to have an origin option that would allow the user to fine tune the casting? For example, in R the base::as.Date() function has such an argument

> as.Date(32, origin = "1970-01-02")
[1] "1970-02-03"

We have a potential workaround in R (once we support date & duration arithmetic), but I was wondering if there might me more general interest for this.

A secondary aspect (as my R example shows) R support casting to date not only from integers, but also doubles. Would there be interesting in that? Need be I can split this into several tickets.

Are there any plans in either of these 2 directions?

Issue Links

• is depended upon by: ARROW-15807 [R] Update as.Date() to support direct casting from double/float
• is depended upon by: ARROW-15799 [R] Update as.Date() to support an origin different from epoch