Some missing format symbols

[chadselph]

I found some (obscure) formatting fields that are missing from this reference: https://docs.oracle.com/en/java/javase/11/docs/api/java.base/java/time/format/DateTimeFormatter.html#patterns

• g - modified-julian-date-number
• B - period-of-day
• v - generic time-zone name

After comparing different versions of the docs it looks like they were added in different versions between 8 and 11.