> Can a rule expeess such calculated fields like "set virtual date at 3 month before transaction date"?
hledger's CSV rules can't do this, no. You'd need to either do that manually, or write a custom conversion script (or a custom preprocessor that modifies the CSV before hledger sees it).
> That's good for forecasting, but I don't see how to write automatic rules that ensure the accrued amount = billed amount.
Similar answer, if you wanted to generate those verbose entries from a single CSV record, it would need some manual entry or a custom preprocessor script. hledger's CSV rules will only generate 0 or 1 transactions per CSV record.
hledger's CSV rules can't do this, no. You'd need to either do that manually, or write a custom conversion script (or a custom preprocessor that modifies the CSV before hledger sees it).
> That's good for forecasting, but I don't see how to write automatic rules that ensure the accrued amount = billed amount.
Similar answer, if you wanted to generate those verbose entries from a single CSV record, it would need some manual entry or a custom preprocessor script. hledger's CSV rules will only generate 0 or 1 transactions per CSV record.
What about the --average option ?