The latest version of Quick Featured Images Pro (QFIP) supplements the time filter by the start day and the end day of a time period. This allows the time filter to be set even finer.
So far one could adjust the time filter to the month only. In the case of a very large number of posts within one month, this was inaccurate. With the version 6.2 of QFIP the time filter can be set exactly to the day.
In addition, all translations were revised.