save the `ts` column into test.xlsx ``` ts 2023-10-31 00:39:00 ``` convert test.xlsx to test.csv: ```bash xlsx2csv test.xlsx test.csv --dateformat '%Y-%m-%d %H:%M:%S' ``` the datetime `2023-10-31 00:39:00` is convert to `2023-10-31 00:39:00`, with one second lost(run `head test.csv`): ``` ts 2023-10-31 00:38:59 ```