Django DateField default options
Question:
I have a model which has a date time field:
date = models.DateField(_("Date"), default=datetime.now())
When I check the app in the built in django admin, the DateField also has the time appended to it, so that if you try to save it an error is returned. How do I make the default just the date? (datetime.today() isn’t working either)
Answers:
Your mistake is using the datetime module instead of the date module. You meant to do this:
from datetime import date
date = models.DateField(_("Date"), default=date.today)
If you only want to capture the current date the proper way to handle this is to use the auto_now_add parameter:
date = models.DateField(_("Date"), auto_now_add=True)
However, the modelfield docs clearly state that auto_now_add and auto_now will always use the current date and are not a default value that you can override.
This is why you should always import the base datetime module: import datetime, rather than the datetime class within that module: from datetime import datetime.
The other mistake you have made is to actually call the function in the default, with the (). This means that all models will get the date at the time the class is first defined – so if your server stays up for days or weeks without restarting Apache, all elements will get same the initial date.
So the field should be:
import datetime
date = models.DateField(_("Date"), default=datetime.date.today)
DateField/DateTimeField.auto_now_add
Automatically set the field to now when the object is first created. Useful for creation of timestamps. Note that the current date is always used; it’s not just a default value that you can override. So even if you set a value for this field when creating the object, it will be ignored.
Source: Django
doc
This should do the trick:
models.DateTimeField(_("Date"), auto_now_add = True)
date = models.DateTimeField(default=datetime.now, blank=True)
You could also use lambda. Useful if you’re using django.utils.timezone.now
date = models.DateField(_("Date"), default=lambda: now().date())
I think a better way to solve this would be to use the datetime callable:
from datetime import datetime
date = models.DateField(default=datetime.now)
Note that no parenthesis were used. If you used parenthesis you would invoke the now() function just once (when the model is created). Instead, you pass the callable as an argument, thus being invoked everytime an instance of the model is created.
Credit to Django Musings. I’ve used it and works fine.
django hint:
HINT: It seems you set a fixed date / time / datetime value as default for this field. This may not be what you want. If you want to have the current date as default, use django.utils.timezone.now
I tried the below on Django version 4.1.7 and worked perfectly!
from datetime import datetime, date
class Example(models.Model):
purchase_date = models.DateField(auto_now_add=False, auto_now=False, blank=True)
def __str__(self):
return f"{self.str(purchase_date)}"
Returning this is entirely optional.
Working perfectly either you return the string or not.
I have a model which has a date time field:
date = models.DateField(_("Date"), default=datetime.now())
When I check the app in the built in django admin, the DateField also has the time appended to it, so that if you try to save it an error is returned. How do I make the default just the date? (datetime.today() isn’t working either)
Your mistake is using the datetime module instead of the date module. You meant to do this:
from datetime import date
date = models.DateField(_("Date"), default=date.today)
If you only want to capture the current date the proper way to handle this is to use the auto_now_add parameter:
date = models.DateField(_("Date"), auto_now_add=True)
However, the modelfield docs clearly state that auto_now_add and auto_now will always use the current date and are not a default value that you can override.
This is why you should always import the base datetime module: import datetime, rather than the datetime class within that module: from datetime import datetime.
The other mistake you have made is to actually call the function in the default, with the (). This means that all models will get the date at the time the class is first defined – so if your server stays up for days or weeks without restarting Apache, all elements will get same the initial date.
So the field should be:
import datetime
date = models.DateField(_("Date"), default=datetime.date.today)
DateField/DateTimeField.auto_now_add
Automatically set the field to now when the object is first created. Useful for creation of timestamps. Note that the current date is always used; it’s not just a default value that you can override. So even if you set a value for this field when creating the object, it will be ignored.
Source: Django
doc
This should do the trick:
models.DateTimeField(_("Date"), auto_now_add = True)
date = models.DateTimeField(default=datetime.now, blank=True)
You could also use lambda. Useful if you’re using django.utils.timezone.now
date = models.DateField(_("Date"), default=lambda: now().date())
I think a better way to solve this would be to use the datetime callable:
from datetime import datetime
date = models.DateField(default=datetime.now)
Note that no parenthesis were used. If you used parenthesis you would invoke the now() function just once (when the model is created). Instead, you pass the callable as an argument, thus being invoked everytime an instance of the model is created.
Credit to Django Musings. I’ve used it and works fine.
django hint:
HINT: It seems you set a fixed date / time / datetime value as default for this field. This may not be what you want. If you want to have the current date as default, use django.utils.timezone.now
I tried the below on Django version 4.1.7 and worked perfectly!
from datetime import datetime, date
class Example(models.Model):
purchase_date = models.DateField(auto_now_add=False, auto_now=False, blank=True)
def __str__(self):
return f"{self.str(purchase_date)}"
Returning this is entirely optional.
Working perfectly either you return the string or not.