COUNTIFS For Dates, When Dates Have Time Value Too? COUNTIF too.
See how to:
(00:10) COUNTIFS with Date Criteria that is matched up against a column with Data Times will not work.
(00:55) Examine Date and Time values under Number Formatting
(01:31) Helper Column Solution with INT and COUNTIFS or COUNTIF
(02:41) Single Cell Array Formula with SUMPRODUCT, INT functions.