Django validate DateTime

class PriceOptionForm(forms.ModelForm):
    # some normal ModelForm setup goes here
    def clean(self):
        cleaned_data = super(PriceOptionForm, self).clean()
        from_time = cleaned_data.get("from_time")
        end_time = cleaned_data.get("end_time")

        if from_time and end_time:
            if end_time < from_time:
                raise forms.ValidationError("End time cannot be earlier than start time!")
        return cleaned_data

(function () {
    // overrides the jquery date validator method
    jQuery.validator.methods.date = function (value, element) {
        // All dates are valid....
        return true;
    };
})(jQuery);

(function () {
    // overrides the jquery date validator method
    jQuery.validator.methods.date = function (value, element) {
        // We want to validate date and datetime
        var formats = ["DD/MM/YYYY", "DD/MM/YYYY HH:mm"];
        // Validate the date and return
        return moment(value, formats, true).isValid();
    };
})(jQuery, moment);

# Create your views here.
def index(request):
    form = validform(request.GET or None)
    return render(request,'index.html',{'form':form})

<input type="text" pattern="/hari/">

def __init__(self, *args, **kwargs):
    super().__init__(*args, **kwargs)
    self.fields['firstname'].widget.attrs.update({'pattern': '/hari/'})