How to calculate frequency received data from time column?

Hi Bit2021 ,

I created a sample pbix file(see attachment), please check whether that is what you want. Assuming the date time is on the same day:

1. Extract the millisecond in Power Query Editor

2. Create a calculated column to get the difference of the times

XMillisecond diff =
VAR _pretime =
    CALCULATE (
        MAX ( 'Datetime'[date_time] ),
        FILTER (
            ALL ( 'Datetime' ),
            'Datetime'[date_time] < EARLIER ( 'Datetime'[date_time] )
        )
    )
VAR _premsecond =
    CALCULATE (
        MAX ( 'Datetime'[Milliseconds] ),
        FILTER (
            ALL ( 'Datetime' ),
            'Datetime'[date_time] < EARLIER ( 'Datetime'[date_time] )
        )
    )
RETURN
    IF (
        ISBLANK ( _pretime ),
        BLANK (),
        DATEDIFF ( _pretime, 'Datetime'[date_time], SECOND ) * 1000 + ( Datetime[Milliseconds] - _premsecond )
    )

3. Create a card visual using the above calculated column with aggregation function: Average just as below screenshot

Best Regards