I've installed SFI development version on MW 1.19 and SMW 1.7 and SF 2.5.2.
In the form I use:
{{{field|Startdatum gepland|property=Startdatum gepland|input type=datepicker}}}
It appears a textbox in the form and i get the followin Javascript error:
Uncaught TypeError: Cannot read property 'regional' of undefined TestCluster:399 (anonymous function) TestCluster:399 fire load.php:14 self.fireWith load.php:15 jQuery.extend.ready load.php:6 DOMContentLoaded load.php:12