Updating from flatpickr v2

Breaking changes in flatpickr v3 have been kept to a minimum to ensure an easy upgrade path for users.

Deprecation of the utc option

Motivation

The utc option was a hack using date manipulation.
It didn’t yield the correct timezone.
Resulting dates were not always accurate.

Upgrade path

Use the dateFormat: "Z" option, which is a shortcut for the ISO date format.
It contains the correct timezone information and is supported by nearly every database.

Additionally I recommend using the altInput: true option to display a nicer date to the user.
Any existing date formats using a Z must be escaped dateFormat: "dHi\\Z M y".

Simplified invocation

Motivation

In v2, users would often get confused about which invocation syntax to use.
There was new Flatpickr() which only supported elements and flatpickr() which only supported selector strings.

It wasn’t always easy to remember, and the two are now merged in v3.

Upgrade path

For those using flatpickr with require() (webpack and other bundlers) - great!
There is nothing to change and you can safely upgrade to v3.

For those using flatpickr with <script src=".../flatpickr.js"... - only a single change is necessary.
Simply find and replace Flatpickr with flatpickr in your scripts.

Note that this also includes statements like Flatpickr.defaultConfig....
Just swap out Flatpickr for flatpickr and you’re good to go.