Hey Raphael,
MTD is period between start of the month and current date or date under consideration. In this case your MTD will not be 40, it will be 20 only if the date under consideration is 15th.
In case 5 conversions happen on 16th, and the date for MTD is 16th, your MTD will be 25.
Hope this helps.
Regards,
Sanmeet