The month the budget starts in (1-12, and the month's name). The budget always covers the twelve months from this start; on writes only the id is used.

The budget's status (budget_status_draft or budget_status_published). On writes, provide either the id or the code; the code wins when both are set.

The accounting tag group the budget tracks (id and name), when one is selected. Only the id is used on writes; omit it to clear the tag group.

The tag applied by default to the budget's amounts (id and name), when one is selected. Only the id is used on writes; the tag must belong to the selected tag group.

The funds the budget covers. On writes, provide each fund as just its id; omit the list to leave the funds unchanged.

The accounts the budget covers. On writes, provide each account as just its id; omit the list to leave the accounts unchanged.