If the assets are created before posting the invoice, they wouldn't have a name and the "code" field of the assets will be empty, but they would have the invoice name.
* There's no need of forcing to create such records if your fiscal years are regular ones.
* FY date range computation duplicates code that is already on core.
* DummyFY is a good idea, but was not used at all. Now it is.
This way, other method_time mechanism like localization ones is able to overwrite it.
You also got an error of variable `number` not set due to previous code. Although no
alternate implementation for a new method_time, now you don't have any error,
fallbacking to standard proportional repartition.