diff --git a/R/slide.R b/R/slide.R
index e1e00c587..c590c25b0 100644
--- a/R/slide.R
+++ b/R/slide.R
@@ -646,7 +646,7 @@ epi_slide_opt <- function(
   if ("new_col_name" %in% provided_args || ".new_col_name" %in% provided_args) {
     cli::cli_abort(
       "epi_slide_opt: the argument `new_col_name` is not supported for `epi_slide_opt`. If you want to customize
-      the output column names, use `dplyr::rename` after the slide.",
+      the output column names, use `.prefix =`, `.suffix =`, or `.new_col_**names** =`.",
       class = "epiprocess__epi_slide_opt__new_name_not_supported"
     )
   }
diff --git a/R/utils.R b/R/utils.R
index 9caa6ad5b..06876f08e 100644
--- a/R/utils.R
+++ b/R/utils.R
@@ -1137,7 +1137,7 @@ time_delta_to_n_steps <- function(time_delta, time_type) {
       week = "weeks",
       cli_abort("difftime objects not supported for time_type {format_chr_with_quotes(time_type)}")
     )
-    units(time_delta) <- output_units # converts number accordingly, doesn't just set attr
+    units(time_delta) <- output_units # converts number to represent same duration; not just attr<-
     n_steps <- vec_data(time_delta)
     if (!is_bare_integerish(n_steps)) {
       cli_abort("`time_delta` did not appear to contain only integerish numbers
@@ -1164,7 +1164,7 @@ time_delta_to_n_steps <- function(time_delta, time_type) {
 time_type_unit_abbrs <- c(
   day = "d",
   week = "w",
-  yearmon = "m"
+  yearmonth = "m"
 )
 
 time_type_unit_abbr <- function(time_type) {
diff --git a/man/time_delta_to_n_steps.Rd b/man/time_delta_to_n_steps.Rd
new file mode 100644
index 000000000..0f9325be4
--- /dev/null
+++ b/man/time_delta_to_n_steps.Rd
@@ -0,0 +1,31 @@
+% Generated by roxygen2: do not edit by hand
+% Please edit documentation in R/utils.R
+\name{time_delta_to_n_steps}
+\alias{time_delta_to_n_steps}
+\title{Convert a time delta to a compatible integerish number of steps between time values}
+\usage{
+time_delta_to_n_steps(time_delta, time_type)
+}
+\arguments{
+\item{time_delta}{a vector that can be added to time values of time type
+\code{time_type} to arrive at other time values of that time type, or
+\ifelse{html}{\href{https://lifecycle.r-lib.org/articles/stages.html#experimental}{\figure{lifecycle-experimental.svg}{options: alt='[Experimental]'}}}{\strong{[Experimental]}} such a vector with Inf/-Inf entries mixed
+in, if supported by the class of \code{time_delta}, even if \code{time_type} doesn't
+necessarily support Inf/-Inf entries. Basically a slide window arg but
+without sign and length restrictions.}
+
+\item{time_type}{as in \code{\link{validate_slide_window_arg}}}
+}
+\value{
+\link[rlang:is_integerish]{bare integerish} vector (with possible
+infinite values) that produces the same result as \code{time_delta} when added
+to time values of time type \code{time_type}. If the given time type does not
+support infinite values, then it should produce +Inf or -Inf for analogous
+entries of \code{time_delta}, and match the addition result match the addition
+result for non-infinite values, and product +Inf / -Inf when match the sign
+and of \code{time_delta}.
+}
+\description{
+Convert a time delta to a compatible integerish number of steps between time values
+}
+\keyword{internal}
diff --git a/tests/testthat/test-epi_slide.R b/tests/testthat/test-epi_slide.R
index 006368d0b..a113610c5 100644
--- a/tests/testthat/test-epi_slide.R
+++ b/tests/testthat/test-epi_slide.R
@@ -755,3 +755,61 @@ test_that("no dplyr warnings from selecting multiple columns", {
   )
   expect_equal(multi_slid_select, multi_slid)
 })
+
+test_that("epi_slide_opt output naming features", {
+  multi_columns <- dplyr::bind_rows(
+    dplyr::tibble(geo_value = "ak", time_value = test_date + 1:200, value = 1:200, value2 = -1:-200),
+    dplyr::tibble(geo_value = "al", time_value = test_date + 1:5, value = -(1:5), value2 = 1:5)
+  ) %>%
+    as_epi_df() %>%
+    group_by(geo_value)
+  multi_columns_weekly <- dplyr::bind_rows(
+    dplyr::tibble(geo_value = "ak", time_value = test_date + 7*(1:200), value = 1:200, value2 = -1:-200),
+    dplyr::tibble(geo_value = "al", time_value = test_date + 7*(1:5), value = -(1:5), value2 = 1:5)
+  ) %>%
+    as_epi_df() %>%
+    group_by(geo_value)
+  yearmonthly <-
+    tibble::tibble(geo_value = 1,
+                   time_value = tsibble::make_yearmonth(2000, 1) + 1:30 - 1,
+                   value = 1:30 %% 2 == 0) %>%
+    as_epi_df() %>%
+    group_by(geo_value)
+
+  # Auto-naming:
+  # * Changing .f and .window_size:
+  expect_equal(
+    multi_columns %>% epi_slide_opt(value2, frollmean, .window_size = 14) %>% names(),
+    c(names(multi_columns), "value2_14dav")
+  )
+  expect_equal(
+    multi_columns %>% epi_slide_opt(value2, slide_mean, .window_size = as.difftime(14, units = "days")) %>% names(),
+    c(names(multi_columns), "value2_14dav")
+  )
+  expect_equal(
+    multi_columns %>% epi_slide_opt(value2, slide_sum, .window_size = Inf) %>% names(),
+    c(names(multi_columns), "value2_running_sum")
+  )
+  # * Changing .f and .align:
+  expect_equal(
+    multi_columns %>% epi_slide_opt(value2, slide_min, .window_size = 14, .align = "center") %>% names(),
+    c(names(multi_columns), "value2_14dcmin")
+  )
+  expect_equal(
+    multi_columns %>% epi_slide_opt(value2, slide_max, .window_size = 14, .align = "left") %>% names(),
+    c(names(multi_columns), "value2_14dlmax")
+  )
+  # * Changing .f, time_type, .window_size:
+  expect_equal(
+    multi_columns_weekly %>% epi_slide_opt(value2, slide_prod, .window_size = 2) %>% names(),
+    c(names(multi_columns_weekly), "value2_2wprod")
+  )
+  expect_equal(
+    multi_columns_weekly %>% epi_slide_opt(value2, slide_prod, .window_size = as.difftime(2, units = "weeks")) %>% names(),
+    c(names(multi_columns_weekly), "value2_2wprod")
+  )
+  expect_equal(
+    yearmonthly %>% epi_slide_opt(value, slide_any, .window_size = 3) %>% names(),
+    c(names(yearmonthly), "value_3many") # not the best name, but super unlikely anyway
+  )
+})