hi,master
http://webix.com/snippet/abb00f21
press button can show date,default today 
but, if i change year , 2016 changed 2015 ,press the button, show date is not change.Because I didn’t click the calendar?
The value has not changed, then why is the selected appearance.
Yep, that looks like a bug - the value should be automatically selected for a “month” calendar in this case. We will add a fix in the nearest release.
As a temp solution, you can catch the onAfterZoom event and set the new value manually: http://webix.com/snippet/e565da6b
thanks,i would like change the year that month is not selected better