It seems obvious, but a native datepicker feature in Excel would be super useful.
So for example, if you set a cell to a particular date format - then you should be able to (when selecting the cell), get an option to open a datepicker and then click on the date, then Excel will input that date however the cell has been formatted.
I believe there are 3rd party add-ons which do this, but it'd be really nice to have this implemented natively.
Mark Burks commented
I agree wholeheartedly. It is a wonderful idea. I have to say that I think a solid DatePicker is all but essential to Excel's core functionalities, and while enormous efforts have been dedicated to the development of higher level mathematical and logical functions, a smooth-functioning input tool for date and time values would be a golden treasure to those working at user interface. I am puzzled that the solutions to this need seem to come and go haphazardly.