The SQL Standard has interval X and interval X to Y types, which can be seen as wrappers around numeric where the Y part is the fractional part. I propose to add Java types to Hibernate for these interval types, which extend java.lang.Number. These special types will receive some methods to interact with Temporal types and map to the corresponding SQL interval types, or numeric/decimal as fallback.

Since Oracle only supports 2 interval types, I would suggest we limit ourselves to these for now:

• YearToMonthInterval for interval year to month
• DayToSecondInterval for interval day to second for a precision up to nanoseconds

We can add others later though if needed and emulate these through the numeric type then.

As a side note, we already support the type interval second which java.time.Duration maps to if possible.