Count Dates in a List of dates for every employee for every month

Hi Experts,
I need a formula to arrive at number days that an employee has worked in a given month. There may be three or four customer visits he would have done on a single day, but the count for days has to be taken as 1 only like his attendance. Ex: if there are 3 entries of 02/01/2021 for Engineer A then the count of date should be 1 only for that month.
Attachment 28568

The engineer column and arrive date columnsAttachment 28569 are highlighted in the attached file, please support with a formula to arrive each engineer worked days in that month.

Thanks in Advance

Raj

Pivot table

Hi Mana,
Pivot table is not the solution, i have figured it out myself. =SUM(IF(FREQUENCY(IF(Engineer=A4,Worked_Days),Worked_Days),1)) has given me result.

Raj

Thank you for sharing the solution. I'm sure it will help many people. :clap: