dragosmg commented on a change in pull request #12433:
URL: https://github.com/apache/arrow/pull/12433#discussion_r817566088



##########
File path: r/R/dplyr-funcs-type.R
##########
@@ -76,6 +76,60 @@ register_bindings_type_cast <- function() {
   register_binding("as.numeric", function(x) {
     Expression$create("cast", x, options = cast_options(to_type = float64()))
   })
+  register_binding("as.Date", function(x,
+                                       format = NULL,
+                                       tryFormats = "%Y-%m-%d",
+                                       origin = "1970-01-01",
+                                       tz = "UTC") {
+
+    if (call_binding("is.Date", x)) {
+      # base::as.Date() first converts to the desired timezone and then 
extracts
+      # the date, which is why we need to go through timestamp() first
+      return(x)
+
+    # cast from POSIXct
+    } else if (call_binding("is.POSIXct", x)) {
+      if (tz == "UTC") {
+        x <- build_expr("cast", x, options = cast_options(to_type = 
timestamp(timezone = tz)))
+      } else {
+        abort("`as.Date()` with a timezone different to 'UTC' is not supported 
in Arrow")
+      }
+
+    # cast from character
+    } else if (call_binding("is.character", x)) {
+      # this could be improved with tryFormats once strptime returns NA and we
+      # can use coalesce - https://issues.apache.org/jira/browse/ARROW-15659
+      # TODO revisit once https://issues.apache.org/jira/browse/ARROW-15659 is 
done
+      if (is.null(format)) {
+        if (length(tryFormats) == 1) {
+          format <- tryFormats[1]
+        } else {
+          abort("`as.Date()` with multiple `tryFormats` is not supported in 
Arrow yet")
+        }
+      }
+      x <- build_expr("strptime", x, options = list(format = format, unit = 
0L))

Review comment:
       Done. Again, the reason I wrote it like I did was to leave us (_imho_) 
in the best position for the follow-up work. 




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