скрара попасть внутрь атрибута
#Given
<time datetime="2020-09-01T11:48:24-03:00" itemprop="datePublished">a given text</time>
# to get the attribute value datetime:
getData = response.css('time::attr(datetime)').get()
# output
'2020-09-01T11:48:24-03:00'
marcofaga