Counting numbers per hour between a start and end time between two dates

Hi  Aizhanz ,

What is the final result you want? See the number of employees per hour (0 to 23)?Will the start time and end time of attend span multiple days? Or is it like 4982659, where the start and end times are not on the same day, but the end time is only on the next day at some point? If the others also have start and end times either on the same day or like 4982659, you can change your calculated column countid as follows, please find the details in the attachment...

countrid = 
CALCULATE (
    COUNTROWS ( 'Table' ),
    FILTER (
        'Table',
        IF (
            DAY ( 'Table'[Start_time] ) = DAY ( 'Table'[End_time] ),
            HOUR ( 'Table'[Start_time] ) <= Table_temp[Value]
                && HOUR ( 'Table'[End_time] ) >= Table_temp[Value],
            (
                HOUR ( 'Table'[Start_time] ) <= 'Table_temp'[Value]
                    && 'Table_temp'[Value] <= 24
            )
                || (
                    HOUR ( 'Table'[End_time] ) >= 0
                        && 'Table_temp'[Value] <= HOUR ( 'Table'[End_time] )
                )
        )
    )
)

If the above one can't help you get the desired result, please provide some sample data in your tables (exclude sensitive data) with Text format and your expected result with backend logic and special examples. It is better if you can share a simplified pbix file. You can refer the following link to upload the file to the community. Thank you.

How to upload PBI in Community

Best Regards