text: from datetime import datetime
  from typing import Literal, Optional, Union
  
  from pydantic import BaseModel
  
  
  class RelativeDate(BaseModel):
      date: Optional[Union[datetime, str]]
      operator: Literal['from', 'until', 'before', 'after']
      quantity: int
      duration: Literal['year', 'quarter', 'month', 'week', 'day']
  