Here is a bug with importing and exporting dates to/from Google sheets.
a) One can set the date format for Import/Export to yyyyMMdd (this is highly useful to allow data to be used in Google Data Studio)
b) This exports a Date field (not a time date field) in the format 20181019 (which is good)
c) However it does not work on import;
If one sets the date in the google sheet to the same value 20181019 then this imports as 1 January 1970
i.e the import requirement and export output do not match, making it impossible to edit the google sheet
Curiously if one types 20180225 23:06:13 (in other words including a time even though it is a date only field) it does import as the correct date, but the google sheet is then incorrect
It would be great if this could be fixed, because using Google Data Studio from memento is stupendous.