Previous blog post I presented solution, where you can have prefixed date selection in model-driven app. For that you should create drop down column based on choice field. Then you hide the actual date field, offer the drop down in user interface and background use Power Automate to update the value user selected to the actual date field.
Since we are talking about dates and time goes by all the time, these prefixed dates usually needs to be changed. This can be done with another scheduled Power Automate flow. If are not picky on the exact dates, then you could pass the date conditions and just schedule it running once a month or something like that.
Power Automate that updates the choice values
Since I want to have exact dates and cannot be sure when it will be running, I scheduled it to be run every day and check the date in the flow logic. Then I created two variables for the current date and month. I need to use dot (.) so that I have separate the value – without it does not put the value if you use just single letter in the format string.
formatDateTime(utcNow(), 'd.') formatDateTime(utcNow(), 'M.')

In this solution we always show the first date of a month, this is why I scheduled it to be run every day and set this kind of condition to terminate the execution if it is not the first day of the month. With this solution I can be sure, that when there is need for update the dates, those will be updated the first day of the month and user could not select dates that are not offered to be selected.

Then you need to decide which dates you want the update to run. Create a switch clause and set the month variable as the on statement. Then create cases for each month you want your choice update to run.

Then finally add to each case the date removal and adding which you want to do. Use the Dataverse unbound action DeleteOptionValue and InsertOptionValue. Since we are using the datevalues hand-in-hand with label, we know which value to remove. 1.1.2026 is 112026 and so on.
formatDateTime(utcNow(), '11yyyy')

For inserting the expressions are
formatDateTime(addDays(utcNow(), 1095), '11yyyy') formatDateTime(addDays(utcNow(), 1095), '1.1.yyyy')
Remember to test your Power Automate flow. You might set d and M variables fixed values when testing. This way you could simulate all the dates that will be faced in future and be sure, that you remove and add the correct choices.