Check if value is added more than once per date

[Peter39]

Hi everybody!
I'm trying to move our Excel spreadsheet to Airtable to simplify things ans automate something.
The spreadsheets is just a list of activity that we need to do (we rent stuff), have a look at the screenshot.

Question: is there a way to transform this spreadsheet into a Airtable app? I need to be able to edit every field in the table, without using a form for each row, it would be too long.
If this is possible, my idea would be to have a single "technician" and "Van" column each with a multi option selection, but since we can have multiple installation per day, is there a way to get an alert if I select the same technician for 2 row in the same day?
Is there a way to highlight/separate/color all the row that have the same day?
Sorry if these are silly question, but I'm just starting with Airtable and so far...I like it!!!
Thanks!