old_contents: from rest_framework import serializers
  from .models import Condition, Entry
  
  class ConditionSerializer(serializers.ModelSerializer):
      class Meta:
          model = Condition
          fields = ('description', 'condition', 'serial', 'uuid')
          
  class EntrySerializer(serializers.ModelSerializer):
      class Meta:
          model = Entry
          fields = ('uuid', 'lane', 'item', 'value', 'unit')
          
new_contents: from rest_framework import serializers
  from .models import Condition, Entry
  
  class ConditionSerializer(serializers.ModelSerializer):
      class Meta:
          model = Condition
          fields = ('description', 'condition', 'serial', 'uuid', 'created_at')
          
  class EntrySerializer(serializers.ModelSerializer):
      class Meta:
          model = Entry
          fields = ('uuid', 'lane', 'item', 'value', 'unit', 'created_at')
          
subject: Add date-time field in serializer.py