How can I make data validation only capture certain data from one cell?

Question

Google Sheets

I need to make data validation output results based only on the date in the cell (dd.mm.yyyy), but not take into account the time after the date in the same cell [dd.mm.yyy hh:mm:ss]

then yes, conditionally, I need to display several items with the same date, not taking into account the time, and accordingly, so that the filter function also reacts only to the date in the cell, but at the same time displays it in full, that is, with the date and time

Answer 1

The simplest is to make the second column for the date, where each cell refers to the full date and discards the fractional part (like a number).