Hi @janagha,
Although, there’s an updated version of the date picker in the Capture app which allows you to select the year (see image), however, even this updated version sticks to the same ‘date format’, and I understand from your question is that you request to change the date format itself? So an enrollment date would be (YYYY)? Would you like to describe the use case? Maybe we can create a feature request. 
I know that it might be inconvenient if date and month are irrelevant for example in your use case, but you will always be able to filter by year when it comes to analytics & reports. Please share your opinion.
Thanks!