import datetime as dt
import panel as pn

pn.extension()

datetime_range_slider = pn.widgets.DatetimeRangeSlider(
    name='Datetime Range Slider',
    start=dt.datetime(2017, 1, 1), end=dt.datetime(2019, 1, 1),
    value=(dt.datetime(2017, 1, 1), dt.datetime(2018, 1, 10)),
    step=10000
)

datetime_range_slider

datetime_range_slider.value

str_format = pn.widgets.DatetimeRangeSlider(
    name='Datetime Range Slider',
    start=dt.datetime(2017, 1, 1), end=dt.datetime(2019, 1, 1),
    value=(dt.datetime(2017, 1, 1), dt.datetime(2018, 1, 10)),
    step=10000,
    format='%Y-%m-%dT%H:%M:%S'
)

str_format

pn.Row(datetime_range_slider.controls(jslink=True), datetime_range_slider)