Issue with year parsing

[jamesrweb]

This timestamp can be parsed correctly as shown here:

In my application, the createdAt value is sent in via JS, parsed correcly via Json.Decode.int and converted to a Posix correctly via millisToPosix as shown here:

However, when using the formatter with the following configuration:

...
 Html.text <| formatPosixToString Time.utc <| User.createdAt user
...

formatPosixToString : Time.Zone -> Time.Posix -> String
formatPosixToString =
    DateFormat.format
        [ DateFormat.monthNameFull
        , DateFormat.text " "
        , DateFormat.dayOfMonthSuffix
        , DateFormat.text ", "
        , DateFormat.yearNumber
        , DateFormat.text " at "
        , DateFormat.hourFixed
        , DateFormat.text ":"
        , DateFormat.minuteFixed
        , DateFormat.text ":"
        , DateFormat.secondFixed
        , DateFormat.text " "
        , DateFormat.amPmUppercase
        ]

It shows the following:

Quite confusing... any ideas?