There are two solutions to your question::
1. Widget edit :: You can customize/create your own widget in Mendix.
Mendix has a specific way of configuring your widget through the use of an XML file. For more information and an example, see WidgetName in the AppStoreWidgetBoilerplate repository.
For the full reference on writing a widget XML, see the Build Widgets with XML.
Go through the tutorial and you can design it.
2. Mendix way :: (Comparatively easier)
Step 1: Choose to only display date and month in drop down. It’s a basic customize feature of mendix.
Step 2 : For the year to display in drop down. Create an entity to store year. Use reference selector to populate year attribute.
Step 3 : And on change of date and month, create object and link date time with year attribute. Basically create an association between date and month with year.
Step 4: Place this reference selector right below or above as per your requirement.
Hope this helps. If you have any questions around this please comment down and I will try and help.
Hi Monika Galbote,
Check this module, this seems similar to your use case.