Even though the Pendulum class is a subclass of datetime there are some rare cases where it can't replace the native class directly. Here is a list (non-exhaustive) of the reported cases with a possible solution, if any:

• sqlite3 will use the the type() function to determine the type of the object by default. To work around it you can register a new adapter:

from pendulum import Pendulum
from sqlite3 import register_adapter

register_adapter(Pendulum, lambda val: val.isoformat(' '))

• mysqlclient (former MySQLdb) and PyMySQL will use the the type() function to determine the type of the object by default. To work around it you can register a new adapter:

import MySQLdb.converters
import pymysql.converters

from pendulum import Pendulum

MySQLdb.converters.conversions[Pendulum] = MySQLdb.converters.DateTime2literal
pymysql.converters.conversions[Pendulum] = pymysql.converters.escape_datetime

• django will use the isoformat() method to store datetimes in the database. However since pendulum is always timezone aware the offset information will always be returned by isoformat() raising an error, at least for MySQL databases. To work around it you can either create your own DateTimeField or use the previous workaround for MySQLdb:

from django.db.models import DateTimeField as BaseDateTimeField
from pendulum import Pendulum


class DateTimeField(BaseDateTimeField):

    def value_to_string(self, obj):
        val = self.value_from_object(obj)

        if isinstance(value, Pendulum):
            return value.to_datetime_string()

        return '' if val is None else val.isoformat()