In the documentation for date formats,
epoch_millis has a maximum char length of 13 (year range of 1653 and 2286).
Also true for
DateTime(millis, DateTimeZone.UTC) to construct an immutable Joda DateTime, where
millis is a Java Long value.
millis can certainly accept more than 13 chars of digits.
I'd like to understand why this limit exists when dealing with epochs.
I've opened a GitHub issue and have a PR available, pending the outcome of this discussion.