Java documentation isn't explicit https://docs.oracle.com/javase/7/docs/api/java/text/SimpleDateFormat.html regarding date/time formats.

The format string is not enforced on the parsing side, so any hour format will accept any value. However oracle's behavior is different - if you specify HH vs HH24, then 13-23 is disallowed.

Need to address this by expanding the logic in the format conversion to account for the difference between parsing and formatting.