There's two ways to this.
First one with your button:
- Attach microflow to your button
- Create a variable endDate at the start of dateTime with expression addDays('[%BeginOfCurrentDayUTC%]',1)
- Retrieve in your microflow from database all objects with Servicedate > '[%BeginOfCurrentDayUTC%]' and ServiceDate < $endDate //These are all objects for which an email needs to be sent
- Place a loop and iterate over your objects. In your iterator, place the SendEmail functionality and pass the neccesary parameters based on your objects)
Second option would be to place the retrieve, iterator and send email in a scheduled event which runs once a day you wouldn't need to press the button each day.