Messing with Dart, I seriously do not understand languages which do not have proper date time parsing nor date time formatting (Without the use of third party extensions). You have to use a very specific set of time strings to be able to parse your time (none of which are fully standards compliant), you cannot specify your own formatting - ie you cannot tell it specifically what to look for. And finally you have to pull in a third party package to be able to format the date time. For such common uses you'd think theyd have that in the core library.
Can you use JavaScript libraries to handle date formatting?