In post #1 you said that you have one occurrence. In post #4 you said that you have 447 occurrences. Surely you can see the discrepancy here...
Based on the sample that you shared in post #4, you can try this in D2:
=IF(COUNTIFS(_LastDates[LastDates],">="&A3,_LastDates[LastDates],"<="&B3),"yes","no")
Only 37 of the dates in the LastDates workbook fit in the time slots in the Tabelle1 worksheet.Means, basically on page 1 there should be 447 times "yes" and the rest "no", depending on date/time of the occurrence and date/time of the line in worksheet 1.
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