Vis.js timeline event handler, update database?

Good day,
I am using vis.js timeline, where you can move items around to new dates. See here, double click and move one of the items around and you can see there is an event handler watching for this action:
Timeline | Event listeners

Now what I am curious of is how we can update our database with the new end date after moving these around. We populate the timeline by listing items from our database but that is it, it's just static. The user can move them around if they want but there is no way to save the new information to our database which is what we want.

I have absolutely no idea how to do such a thing or if it's possible. We are not populating the timeline with json or ajax or anything, just straight server side asp scripting. I'd even be happy with a save button to save everything after moving them all, no real need to update the database after every move although if that is the only way to do it then that is great too.

Any advice on how we can make this possible would be great.
Thank you!