This version corrects the Admin issue introduced by V4.4. V4.4.1 is available through the Joomla Updater or for download through your My Downloads area of our website.
Turns out a code change intended for our 5.0dev branch inadvertantly got pushed to the 4.x branch (by me, duh!). The javascript structure in 5.0 will change considerably and part of that change took effect with the inadvertant code change.
We have reverted the code change and released 4.4.1. V4.4 has been retracted.
Sorry for any inconvenience.
See the details here
/*On change of from_date (=this element) set to_date 2 days after.
termin_reservation___bis = full element name of to_date, form_18 = your form id
*/
var to_date_id = 'termin_reservation___bis';
var to_date = Fabrik.getBlock('form_18').formElements.get(to_date_id);
var from_date = this.get('value');
var newDate = new Date(from_date);
newDate.increment('day', 2);
to_date.set(newDate);