use "." as seperator; #702

R/sf.R

@@ -192,9 +192,10 @@ st_as_sf.stars = function(x, ..., as_points = FALSE, merge = FALSE, na.rm = TRUE
 			else { # another exception... time as second dimension
 				e = expand_dimensions(x)
 				if (length(e[-ix]) == 1 && inherits(e[-ix][[1]], c("Date", "POSIXt", "PCICt"))) {
-					names(df) = if (length(nc) > 1)
-							do.call(paste, rev(expand.grid(e[-ix][[1]], names(x))))
-						else
+					names(df) = if (length(nc) > 1) {
+							nm = expand.grid(e[-ix][[1]], names(x))
+							paste(nm[[2]], nm[[1]], sep = ".")
+						} else
 							as.character(e[-ix][[1]])
 				}
 			}