If you need your date data formatted a certain way so that it works well with Treasure Data there are ways that you can do so. Particularly, if you are importing CSV formatted data on Windows and doing a batch import, you can add the --time-format parameter to your import statement. For Example:
td import:prepare --format csv --column-header --time-column 'date' \
--time-format '%%Y-%%m-%%d' t % is a recognized environment variable, so you must use %% to set it.