Adressbook: year only applies when day is selected

[mbohlender]

How to reproduce:
go to contact in adressbook
set complete birthday

select birthday again and try to change the year

Actual result:
year change does not apply unless you also set a day

Expected result:
year change should apply without the need to select a day

[alecpl]

This is jQuery-UI widget, but it should not be hard to extend.

However, I'm not sure about this. When you work on an empty input (the date is not yet selected) a year change will do nothing. What about a month change? It could be more tricky for example when your selected day is 31 January and you switch the month to February. So, will that change not confusing in any way?