diff --git a/CHANGELOG.md b/CHANGELOG.md
index 3c9f43adb..a88fddcab 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -17,6 +17,8 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ### Bug fixes
 
+* Using `update_slider` to update a slider's value to a `datetime` object or other non-numeric value would result in an error. (#649)
+
 ### Other changes
 
 * Documentation updates. (#591)
diff --git a/e2e/bugs/0648-update-slider-datetime-value/app.py b/e2e/bugs/0648-update-slider-datetime-value/app.py
new file mode 100644
index 000000000..64c599323
--- /dev/null
+++ b/e2e/bugs/0648-update-slider-datetime-value/app.py
@@ -0,0 +1,90 @@
+from __future__ import annotations
+
+import datetime
+from typing import Any, Optional, Union
+
+import shiny.experimental as x
+from shiny import App, Inputs, Outputs, Session, reactive, render, ui
+
+start_time = datetime.datetime(2023, 7, 1, 0, 0, 0, 0, tzinfo=datetime.timezone.utc)
+end_time = start_time + datetime.timedelta(hours=1)
+
+from shiny import App, Inputs, Outputs, Session, module, reactive, render, ui
+
+
+@module.ui
+def slider_with_reset_ui(
+    label: str,
+    value: Union[
+        datetime.datetime,
+        tuple[datetime.datetime, datetime.datetime],
+        list[datetime.datetime],
+    ],
+) -> ui.TagChild:
+    return x.ui.card(
+        ui.input_slider(
+            "times",
+            "Times",
+            start_time,
+            end_time,
+            value,
+            timezone="UTC",
+            time_format="%H:%M:%S",
+        ),
+        ui.output_text_verbatim("txt"),
+        ui.div(ui.input_action_button("reset", label)),
+    )
+
+
+@module.server
+def slider_with_reset_server(
+    input: Inputs,
+    output: Outputs,
+    session: Session,
+    *,
+    min: Optional[datetime.datetime] = None,
+    max: Optional[datetime.datetime] = None,
+    value: Any = None,
+):
+    @output
+    @render.text
+    def txt():
+        if isinstance(input.times(), (tuple, list)):
+            return " - ".join([str(x) for x in input.times()])
+        else:
+            return input.times()
+
+    @reactive.Effect
+    @reactive.event(input.reset)
+    def reset_time():
+        ui.update_slider("times", min=min, max=max, value=value)
+
+
+app_ui = ui.page_fluid(
+    x.ui.layout_column_wrap(
+        "400px",
+        slider_with_reset_ui("one", "Jump to end", start_time),
+        slider_with_reset_ui("two", "Select all", (start_time, start_time)),
+        slider_with_reset_ui("three", "Select all", [start_time, start_time]),
+        slider_with_reset_ui("four", "Extend min", [start_time, end_time]),
+        slider_with_reset_ui("five", "Extend max", [start_time, end_time]),
+        slider_with_reset_ui("six", "Extend min and max", [start_time, end_time]),
+    ),
+    class_="p-3",
+)
+
+
+def server(input: Inputs, output: Outputs, session: Session):
+    slider_with_reset_server("one", value=end_time)
+    slider_with_reset_server("two", value=(start_time, end_time))
+    slider_with_reset_server("three", value=[start_time, end_time])
+    slider_with_reset_server("four", min=start_time - datetime.timedelta(hours=1))
+    slider_with_reset_server("five", max=end_time + datetime.timedelta(hours=1))
+    slider_with_reset_server(
+        "six",
+        min=start_time - datetime.timedelta(hours=1),
+        max=end_time + datetime.timedelta(hours=1),
+    )
+
+
+app = App(app_ui, server)
diff --git a/e2e/bugs/0648-update-slider-datetime-value/test_update_slider_datetime_value.py b/e2e/bugs/0648-update-slider-datetime-value/test_update_slider_datetime_value.py
new file mode 100644
index 000000000..b569d0de7
--- /dev/null
+++ b/e2e/bugs/0648-update-slider-datetime-value/test_update_slider_datetime_value.py
@@ -0,0 +1,54 @@
+from __future__ import annotations
+
+from typing import Optional
+
+from conftest import ShinyAppProc
+from controls import InputActionButton, InputSlider, OutputTextVerbatim
+from playwright.sync_api import Page, expect
+
+
+def test_slider_app(page: Page, local_app: ShinyAppProc) -> None:
+    def check_case(
+        id: str,
+        *,
+        value: tuple[Optional[str], Optional[str]] = (None, None),
+        min: tuple[Optional[str], Optional[str]] = (None, None),
+        max: tuple[Optional[str], Optional[str]] = (None, None),
+    ):
+        slider_times = InputSlider(page, f"{id}-times")
+        btn_reset = InputActionButton(page, f"{id}-reset")
+        out_txt = OutputTextVerbatim(page, f"{id}-txt")
+
+        if value[0] is not None:
+            out_txt.expect_value(value[0])
+        if min[0] is not None:
+            expect(slider_times.loc_irs.locator(".irs-min")).to_have_text(min[0])
+        if max[0] is not None:
+            expect(slider_times.loc_irs.locator(".irs-max")).to_have_text(max[0])
+
+        btn_reset.loc.click()
+
+        if value[1] is not None:
+            out_txt.expect_value(value[1])
+        if min[1] is not None:
+            expect(slider_times.loc_irs.locator(".irs-min")).to_have_text(min[1])
+        if max[1] is not None:
+            expect(slider_times.loc_irs.locator(".irs-max")).to_have_text(max[1])
+
+    page.goto(local_app.url)
+
+    start_time = "2023-07-01 00:00:00"
+    end_time = "2023-07-01 01:00:00"
+
+    check_case("one", value=(start_time, end_time))
+    check_case(
+        "two",
+        value=(f"{start_time} - {start_time}", f"{start_time} - {end_time}"),
+    )
+    check_case(
+        "three",
+        value=(f"{start_time} - {start_time}", f"{start_time} - {end_time}"),
+    )
+    check_case("four", min=("00:00:00", "23:00:00"))
+    check_case("five", max=("01:00:00", "02:00:00"))
+    check_case("six", min=("00:00:00", "23:00:00"), max=("01:00:00", "02:00:00"))
diff --git a/shiny/ui/_input_update.py b/shiny/ui/_input_update.py
index ca455a776..35a34ec52 100644
--- a/shiny/ui/_input_update.py
+++ b/shiny/ui/_input_update.py
@@ -775,8 +775,8 @@ def update_slider(
     session = require_active_session(session)
 
     # Get any non-None value to see if the `data-type` may need to change
-    val = value[0] if isinstance(value, tuple) else value
-    present_val = next((x for x in [val, min, max]), None)
+    val = value[0] if isinstance(value, (tuple, list)) else value
+    present_val = next((x for x in [val, min, max] if x is not None), None)
 
     data_type = None if present_val is None else _slider_type(present_val)
     if time_format is None and data_type and data_type[0:4] == "date":
@@ -785,10 +785,16 @@ def update_slider(
     min_num = None if min is None else _as_numeric(min)
     max_num = None if max is None else _as_numeric(max)
     step_num = None if step is None else _as_numeric(step)
+    if isinstance(value, (tuple, list)):
+        value_num = [_as_numeric(x) for x in value]
+    elif value is not None:
+        value_num = _as_numeric(value)
+    else:
+        value_num = None
 
     msg = {
         "label": label,
-        "value": value,
+        "value": value_num,
         "min": min_num,
         "max": max_num,
         "step": step_num,