Simply create a custom table in Power Query, enter the date shown in the question into a column called Date, and then Split it by a delimiter. No need for spaces on either side of "at" Power BI takes care of the rest:
= Table.SplitColumn(#"Changed Type", "Date", Splitter.SplitTextByDelimiter("at", QuoteStyle.Csv), {"Date.1", "Date.2"}) It will even automatically change the type to Date:
= Table.TransformColumnTypes(#"Split Column by Delimiter",{{"Date.1", type date}, {"Date.2", type time}})