Given a filepath
s, this function will look for the last correctly-parsed date in that string. Given how SafeGraph AWS file structures are, this will give you the date of those files, for example
patterns_backfill/2020/12/14/21/2018/01/01 will give you "2018/01/01".
The filepath to look for a date in.
For backfill data, the date returned will generally be the
start_date for the files. However, for new data, you will want to do
as.Date(find_date(s)) - lubridate::days(9) to get the