Input 2 fields
A simple GUI with 2 inputs for this Reddit post: https://www.reddit.com/r/learnpython/comments/jq17m3/ive_finally_written_my_first_script_for_work_but/
The window will be shown until a button is clicked or closed with an "X". This is called a "One Shot" window. Add an event loop if you want more user interaction.
You can add more advanced features such as adding a popup call to get the date, or adding a Date Chooser button to choose the date. This will be easier for the user and will automatically do a bit of validation of the input.