如何设计一个列以在Django模型中手动添加有效时间段

Question

i have a model namely SubscribePlan here it is

class SubscribePlan(models.Model):

    plan = models.CharField(max_length = 200)
    price = models.IntegerField(default=0)
    validity_period = models.DateTimeField()
    number_of_download = models.IntegerField(default = 0)

here i want to add a validity_period column in such a way where the admin will manually add the validity time.I know that django model provides two different datatypes for Date one is DateField() and another is DateTimeField()

and if i am not wrong ,there is two parameter for DateTimeField() ,one is auto_now and another is auto_now_add .

UPDATE :

But my concern is,i have to provide such a model for the admin where admin can manually put a valid time period assume 24 hours or 48 hours or 1 day or 2 days through the Admin interface or Admin panel.

So in this case what should be the data type of the model where valid time period can be input manually? or if the datatype is DateTimeField then what should be the parameter? in mention i am using django 1.5

Answer 1

I think the validity_period should be Integer Field(or Character Field), because it is not a Date but just a number which can be used for checking a time period, like this:

For example, lets make a function which will check the validity of a Subscription.

for Integer Field

import datetime
def check_validity(start_time ,validity_period):
    if datetime.datetime.now() <= start_time + datetime.timedelta(hours=validy_period):
      return True
    return False

Answer 2

It can also depend on what kind of control(web element) is being used in admin interface for entering the validity period. If the admin interface has a date-time picker or calendar, which returns a DateTime object, for entering the validity period then in your model the validity_period field can be of type DateTimeField() or DateField(). But if admin is providing input like 1 days or 2 days then it should be of IntegerField or CharField.