`%S` means seconds as two digits zero-filled as in `00 to 59` `%f` means seconds as six digits zero-filled as in `00.000 to 59.999` The formatting string '%Y-%m-%d %H:%M:%S.%f' which would produce output like: 2021-07-20 22:31:19.19.275 The correct formatting string is '%Y-%m-%d %H:%M:%f' which would produce output like: 2021-07-20 22:31:19.275