TypeError：必须为整数（获取类型为datetime.datetime）

我想在输入后将gregorian转换为hijri 但是我得到这个错误

TypeError: an integer is required (got type datetime.datetime)

编码

from datetime import datetime
from hijri_converter import convert

war_start = '2011-01-03'

war = datetime.strptime(war_start, '%Y-%m-%d')
war1 = convert.Gregorian(war).to_hijri()

print(war1)