datetime 序列化报错

[HeisenBerg?]

from datetime import datetime
print(datetime.now())
2022-06-29 01:27:38.214869
print(datetime.utcnow())
2022-06-28 17:27:47.372238
from datetime import datetime,timedelta
print(datetime.now() + timedelta(days=1))
2022-06-30 01:28:23.930576

create_time: Optional[datetime] = Field(default_factory=datetime.utcnow(), title='CreateTime')
upload_time: Optional[datetime] = Field(default_factory=datetime.now(), title='UploadTime')
defaultdate= datetime.now() + timedelta(days=1)
schedule_date: Optional[datetime] = Field(default_factory=defaultdate, title='ScheduleTime')

File "D:\Programs\anaconda\lib\json\encoder.py", line 179, in default
raise TypeError(f'Object of type {o.class.name} '
TypeError: Object of type datetime is not JSON serializable

[AmisAdmin]

default_factory 应该是一个可执行函数