11 Best Novel Protein Dog Foods – Wet and Dry Reviews

Protein is a vital component in your dog’s diet, i.e., they are a source of amino acids, which are the basic building blocks of all body tissue, including hair, skin, muscles, and cartilages, and so on. Furthermore, some form part of hormones, enzymes, antibodies as well as support the immunity system, among many other roles.

Familiar sources of protein in canine diets include beef, chicken, pork, eggs, and fish. Lately, there are many foods with turkey and lamb.

Dog food allergies and symptoms

Dog allergies occur when a dog’s immunity falsely or mistakably flags a harmless dietary component as a harmful foreign body or allergen, thereby triggering an immune response (release of antibodies).

Food allergies account for about 10% of the dog allergy cases (1) third behind fleas and environmental allergies.

The exact cause of food allergies in these pets remains unknown studies have shown that continual feeding of a dog with the same type of food for a long time predisposes them to allergies. To make matters worse, as Whole Dog Journal reports, “dogs who display an allergy to one food ingredient are prone to developing allergies to other ingredients over time.”

Furthermore, any dog can suffer from food hypersensitivities, and most diagnosis occurs in dogs. However, studies have placed Terriers, Miniature Schnauzers, German shepherds, Dalmatians, Boxers, Dachshund, Rhodesian ridgebacks, Lhasa Apso, Shar Pei, Labrador Retrievers, Shih Tzu,  Pugs,  Cocker Spaniels, Beagle, Golden Retrievers, Chinese Crested,  Poodles, setters, Pekinese, Collie, crested Chinese, bulldog, and Bichon Frise as more vulnerable. (2, 3, 4, 5)

These hypersensitivities are not the same as intolerance, where a dog’s digestive system cannot handle some dietary components resulting in gastrointestinal troubles.

A study on ‘Critically Appraised Topic on Adverse Food Reactions of Companion Animals (2): Common Food Allergen Sources in Dogs and Cats’ names beef, dairy products, chicken, wheat and lamb as commo allergens in cat and dog foods.

Other lesser common dietary components that trigger food sensitivities include soy, corn, eggs, pork, and fish, while rice with barley, rabbit, kidney beans, and tomato having the least cases.

Signs of food allergies include

• Itchiness characterized by licking, scratching, and biting that may affect the face, ears, paws, forelegs, legs, armpits, perineal areas, or any other body part.
• Irritated skin, dry patches, skin lesions, hotspots, and hair loss as well as  recurring skin and ear infections
• Less common symptoms include G.I. signs such as gassiness, diarrhea, and stomach upsets, vomiting, and so on, while wheezing, sneezing, poor growth, coughing may occur on rare occasions.

Vets use various strategies managing canine food allergies that include therapeutic diets, including hypoallergenic diets like hydrolyzed protein foods, those with limited ingredients, novel protein diets, or home diets with controlled ingredients.

What are novel protein dog foods?

Novel or new protein sources are protein sources that your dog has never exposed to or eaten before. Such sources present little chances of causing hypersensitivities, and they include, venison, bison, herring, salmon, rabbit, duck, kangaroo, horse meat, pheasant, wild boar, quail, ostrich, buffalo, lamb, and turkey.

Since these protein sources are not food in most ordinary canine diets, most dogs have not been exposed to them. Therefore, there are minimal chances that these diets will cause allergic reactions.

However, on lamb, according to Dr. Jennifer Coates, “in the past, lamb and rice was the go-to, over-the-counter combination…, but after it became widely available, it lost most of its efficacy. Rice is probably still okay (it’s easily digested and not very allergenic), but so many dogs have eaten lamb at some point in their lives now that it isn’t really “novel” anymore.

Therefore, if you opt for any diet with lamb, ensure your pet hasn’t eaten it before. Otherwise, it may not be helpful.

At a glance: top novel protein dog foods

Choosing the best novel protein dog foods

The first qualifying factor is the use of a novel protein source that your dog has never eaten before, which will be listed in the ingredients used.

Typical labels to in novel protein diets (NPDs) include limited ingredients, grain-free, natural, for sensitive stomachs, sensitive skin/stomach, and so on.

 In addition to that, these diets should be:

• Complete and balanced for the specific nutritional profile or life stages. Check for the nutritional adequacy statement, which should either be “Food A is formulated to meet the nutritional levels established by the AAFCO Cat Food Nutrient Profiles for all life stages.” Alternatively, check for “Animal feeding tests using AAFCO procedures substantiate that Food A provides complete and balanced nutrition for growing” statement.
• Increase levels of omega-3 and omega-6 fatty acids to support healthy skin and coat.
• Free of any contamination from common allergens like beef, chicken, or wheat, which studies have noted to be higher in dry novel protein diets (6). Proper raw material selection and production process should ensure not contamination occurs.
• They should be correctly labeled. As one study concludes, “widespread issue in pet foods used as elimination diets.
• Use less allergenic carbohydrate sources such as rice, sweet potatoes, potatoes, or lentils or those that are grain-free (which are gluten-free and don’t have barley, corn, rye, wheat, etc.)

Best novel protein dog foods

There are so many novel protein dog foods. However, after looking at several factors, including guaranteed analysis, ingredients, expert comments, user reviews, and ratings, among other factors, we settled on the below.

Note that, while looking at the best novel protein dog foods, we excluded those with unspecified fish meals unless designed for food sensitivities, as well as dried eggs or egg products. However, chicken fat or any other animal fats don’t carry the allergens found in that animal’s protein.

Finally, in the guaranteed analysis, not all guaranteed products recognized by AAFCO as essential. For instance, omega-3, omega-6 fatty acid, ascorbic acid (vitamin C), glucosamine, microorganisms (probiotics), beta-carotene, l-Carnitine, taurine, among others. However, they do have vital roles in a dog’s diet.

1. Natural Balance L.I.D. Limited Ingredient Diets Sweet Potato & Venison Formula Grain-Free Dry Dog Food

If you are looking for the best novel protein for adult dog foods, Natural Balance L.I.D. Limited Ingredient Diets Sweet Potato & Venison Formula Grain-Free for adult dogs should be at the top of your choices.

Key benefits

• Utilizes a limited ingredient formulation with being venison being the only animal protein source, others being potato and pea protein.
• Features a grain-free formulation
• Uses sweet potato, which is not only nutrient-rich but also rarely causes allergens.
• Offers a healthy digestion support
• Fortified with vitamins and minerals

Additional information

• First ingredients: Sweet potatoes, venison, pea protein, potato protein, canola oil (preserved with mixed tocopherols), brewers dried yeast.
• Calories: 3,340 kcal/kg M.E. or an equivalent of 370 kcal/8 oz. cup.
• Guaranteed analysis: Crude protein (min): 20.0%, crude fat (min): 10.0%, crude fiber: (max) 5.0%, moisture (max): 10.0%, calcium (min):  0.8%, phosphorus (min): 0.6%, omega-3 fatty acids (min): 0.50%, omega-6 fatty acids (min): 1.50%.

Natural balance has many other dog foods with limited animal protein sources with Diets Sweet Potato & Venison Formula Grain-Free, a fantastic alternative to buy.

2. Blue Buffalo Basics Limited Ingredient Diet, Grain-Free Formula Turkey & Potato Recipe Adult Dry Dog Food

Adult dogs with sensitivities stand to benefit from this limited ingredient formulation and use turkey as the only animal protein source. These tasty and mouthwatering LifeSource Bits kibbles have the right balance of nutrients, including vitamins, minerals to ensure your pet gets superior nutrition.

Key benefits

• Formulated turkey as the only animal protein source and easy to digest starch that includes potato, peas, and tapioca starch.
• Its grain-free, i.e., has no wheat, corn, soy, or grains that usually have gluten.
• It is free of preservative, flavor, and poultry or chicken by-product meals
• It has added omega fatty acids to support the skin and coat health.
• It has antioxidants that boost immunity and neutralizes free radicals that would otherwise cause oxidative damage.

Additional information

• First ingredients: Deboned turkey, potatoes, turkey meal (source of glucosamine), pea starch, peas, tapioca starch, pea fiber, potato starch, and canola oil.
• Calories: It has 3,503 kcal per kg or an equivalent of 352 kcal per cup (8oz).
• Guaranteed analysis: Crude protein (min): 20.0%, crude fat (min): 12.0%, crude fiber: (max) 6.0%, moisture (max): 10.0%, calcium (min):  0.9%, phosphorus (min): 0.7%, omega-3 fatty acids (min): 0.75%, omega-6 fatty acids (min): 2.25%, Ascorbic Acid (Vitamin C) (min): 100mg/kg and glucosamine (min) 300mg/kg.

If your dog loves the Turkey & Potato Recipe, we can bet he will also enjoy every bite of the Salmon & Potato Recipe.

3. Natural Balance L.I.D. Limited Ingredient Diets Sweet Potato & Venison Formula Grain-Free Canned Dog Food

This Natural Balance Sweet Potato & Venison canned dog food is a perfect choice if you need wet food made with limited ingredients as well as only a single novel protein source. It will ensure the wellbeing and optimum overall health adult dogs, puppies, and pregnant or nursing females.

Key benefits

• Uses venison as its only protein animal source with potato the primary source of carbohydrate
• It will boost your dog’s skin and lustrous coat since added canola and salmon oil are a potent source of omega fatty acids.
• It is easy to digest, will support a healthy digestive system, and boost hydration.
• It is grain-free. Therefore, it will minimize the chances of your pet suffering from grain-related food sensitivities. 

Additional information

• First ingredients: Sweet potatoes, venison broth, venison, potatoes, potato protein, dehydrated potatoes, as well as canola oil and salmon oil, both preserved with mixed tocopherols.
• Calories – It has 1,020 kcal metabolizable energy (M.E.) per kilogram ME or 376 kcal ME/13 oz. can.
• Guaranteed analysis: Crude protein (min): 6.0%, crude fat (min): 4.0%, crude fiber: (max) 2.0%, moisture (max): 78.0%.

4. Wellness Simple Limited Ingredient Diet Grain-Free Salmon & Potato Formula Dry Dog Food

Wellness understands that dogs with sensitivities require purposeful and careful selection of ingredients used in their diets to minimize instances of hypersensitivities while providing complete nourishment. This is nothing short of what this grain-free Salmon & Potato Formula Dry Dog Food will offer your adult canine friend.

Key benefits

• Uses salmon, an uncommon protein source as the only animal protein source to minimize the chances of food-related allergies.
• The formulation uses easy to digest carbohydrates, i.e., peas and potatoes.
• Rich in omega fatty acids (from salmon and flaxseed), which supports your dog’s healthy skin and ensures a luxurious and shiny coat
• Chicory root provides a natural source of prebiotics, vital in promoting gut health.
• Grain-free

Additional information

• First ingredients: Salmon, salmon meal, potatoes, peas, dried ground potatoes, tomato pomace, ground flaxseed, and canola oil.
• Calories: It has 3,487 kcal/kg metabolizable energy (M.E.) or 446 kcal/cup M.E. on as fed basis.
• Guaranteed analysis: Crude protein (min): 25.0%, crude fat (min): 12.0%, crude fiber: (max) 5.0%, moisture (max): 11.0%, omega-3 fatty acids (min): 1.00%, omega-6 fatty acids (min): 1.75%, total lactic acid microorganisms (min): 20, 000, 000 CFU/lb.

To add more variety to your dog’s food, Wellness Simple Limited Ingredient Diet Grain-Free Turkey & Potato Formula Dry Dog Food will work well.

5. Taste of the Wild Pacific Stream Puppy Formula Grain-Free Dry Dog Food

If you have puppies, nursing or pregnant dogs who suffer from food sensitivity, the Taste of the Wild Pacific Stream Puppy Formula Grain-Free Dry Dog Food will be a great choice. This is high in protein and other nutrients that offer a perfect nutritional balance to support growth and optimal health.

Key benefits

• Uses salmon as the only animal protein source
• Formed into smaller crunchy kibbles to make eating more comfortable while offering some dental benefits achieved via chewing action as it reduces tartar buildup.
• Egg-free formulation. Eggs are a common source of allergies.
• Has a blend of antioxidants from fruits, legumes, and vegetables as well as selenium and vitamin E that will support your pet’s immunity and overall wellbeing.  
• Offers guaranteed D.H.A. from salmon oil, suitable for vision and brain development
• The K9 Strain probiotics or microorganisms added after cooking will support immunity and digestive health.

Cons

• The food has a risk of contamination with eggs in the manufacturing facility.

Additional information

• First ingredients: Salmon, ocean fish meal, sweet potatoes, peas, potatoes, canola oil (preserved with mixed tocopherols), pea protein, tomato pomace, smoked salmon, and salmon meal. 
• Calculated calories: 3,600 kcal per kg or  (360 kcal per cup  Metabolizable Energy
• Guaranteed analysis: Crude protein (min): 27.0%, crude fat (min): 15.0%, crude fiber: (max) 5.0%, moisture (max): 10.0%, DHA (docosahexaenoic Acid) (min): 5%, zinc (min): 150 mg/kg, selenium (min): 0.35 mg/kg. Vitamin E (min): 175 IU/kg. Others are omega-3 fatty acids (min): 0.30%, omega-6 fatty acids (min): 1.75%, total microorganisms (Lactobacillus plantarum, Lactobacillus acidophilus, Bacillus subtilis, Bifidobacterium animalis and Enterococcus faecium) (min): 80, 000, 000 CFU/lb.

6. Rachael Ray Nutrish Just 6 Natural Lamb Meal & Brown Rice Limited Ingredient Recipe Dry Dog Food

Just 6 Natural Lamb Meal & Brown Rice is a wholesome dry adult dog food made using limited ingredients, i.e., a blend of only six ingredients besides minerals and vitamins.

Key benefits

• Limited ingredients with lamb as its only protein source. It will provide your dog with the much-needed amino acids, glucosamine, chondroitin, and vitamin B complex.
• Its free corn, soy, wheat or any other ingredients with gluten
• Brown and ground rice are the primary sources of carbohydrates. They are easy to digest and least known to cause food sensitivities. Brown rice is also a good source of fiber needed to boost digestion.
• No poultry by-product meals, artificial colors, flavors or preservatives
• Fiber from brown rice aids in digestion while prebiotics from beet pulp will support digestive system health.
• It is loaded with omega 3 and 6 fatty acids from chicken fats. Expect a shiny coat and healthy skin.

Additional information

• First ingredients: Lamb meal, brown rice, ground rice, dried plain beet pulp, chicken fat (preserved with mixed tocopherols), natural pork flavor,
• Calories: 3,379 kcal per kg or an equivalent of 321 kcal per cup
• Guaranteed analysis: Crude protein (min): 20.0%, crude fat (min): 13.0%, crude fiber: (max) 4.0%, moisture (max): 10.0%, Linoleic acid (min): 1.5%, alpha-Linolenic Acid (min) 0.1% calcium (min): 1.2%, phosphorus (min): 1.0%, zinc (min): 250mg/kg, vitamin E (min): 225 IU/kg, ascorbic acid (vitamin C) (min): 55 mg/kg, glucosamine (min): 400 mg/kg, chondroitin sulfate (min): 200 mg/kg.

7. Hill’s Prescription Diet d/d Canine Potato & Venison Formula

To help manage food and skin sensitivities, your vet may prescribe to you the Hill’s Prescription Diet d/d Canine Potato & Venison Formula for maintenance of adult dogs.

Key benefits

• Its formulation uses limited ingredients and venison as the only animal protein source.
• Improves stool quality and digestion
• Has omega -3, omega-6, and D.H.A. that will promote healthy skin and coat and has neurological, which also has cardiovascular health benefits.  Also, the food will ensure your dog has a healthy skin barrier.
• Doesn’t have grains, soy protein or any ingredients that have gluten
• Has antioxidants that will support immunity.

Cons

• Compared to other brands, it is costly, perhaps because it is a prescribed diet.

Additional information

• First ingredients:  Potatoes, potato starch, venison, potato protein, pork fat, soybean oil, pork flavor, lactic acid,
• Calories: 3736 kcal per kg (371 kcal per 8 oz. cup
• Guaranteed analysis:  Protein: 18.1%, Fat: 16.3%, Crude Fiber: 1.7%, Carbohydrate or NFE: 57.4%, Calcium: 0.79% Phosphorous: 0.57%, Sodium: 0.39%, Potassium: 1.08%, Magnesium: 0.067%, Vitamin C: 273 ppm, Vitamin E: 747 IU/kg, Total Omega-3 FA: 0.77%, Total Omega-6 FA: 3.54%, EPA: 0.207 on dry matter basis.

If you need an excellent canned food alternative, from Hill’s Pet, your dog will enjoy the Duck formula.

8. Earthborn Holistic Meadow Feast Grain-Free Natural Dry Dog Food

Earthborn Holistic Meadow Feast is an adult dog maintenance dry dog food designed to provide high protein and proper nourishment to dogs prone to stomach sensitivity. It will meet all the nutritional needs of your adult dogs (maintenance).

Key benefits

• Uses a single protein source, i.e., premium lamb meal that will provide energy, lean muscle mass, and development. The added L-Carnitine will further help in fat conversion to energy and lean muscle. 
• Has limited ingredients and doesn’t have potatoes, grains, or gluten, giving an excellent choice of a grain-free recipe.
• Features a blend of fruits and vegetables, including apples, blueberries, spinach, carrots, and cranberries for additional nutrients
• Added omega-3 and omega-6 fatty acids for healthy skin, coat and creating a healthy skin barrier

Additional information

• First ingredients: Lamb meal, peas, tapioca, canola oil (preserved with mixed tocopherols), pea protein, pea fiber, flaxseed, natural flavors, blueberries, cranberries, apples, carrots, spinach.
• Calories: 3520 kcal/kg and 370 kcal/cup calculated Metabolizable Energy ME on as fed basis.
• Guaranteed analysis: Crude protein (min): 26.0%, crude fat (min): 15.0%, crude fiber: (max) 5.0%, moisture (max): 10.0%, calcium (min):  1.2%, phosphorus (min): 1.0%, omega-3 fatty acids (min): 1.75%, omega-6 fatty acids (min): 2.1%, Ascorbic Acid (Vitamin C) (min): 100mg/kg and L-Carnitine (min): 50mg/kg, vitamin E (min): 250 IU/kg, and Taurine (min): 0.05%

If your dog happened to like lamb Meadow Feast, you can offer him a variety by considering Rabbit Meal & Pumpkin Limited Ingredient Diet, which his equally good.

9. CANIDAE PURE Real Salmon & Sweet Potato

This tasty and flavorful real salmon and sweet potato formulation a Uses a limited ingredient formulation that uses only eight wholesome ingredients to ensure your adult dog is well nourished without the risk of it suffering from food sensitivities.

Key benefits

• High in protein and uses novel protein source, i.e., salmon and menhaden fish meal.
• It is grain-free, has no soy, meat, or other fillers often blamed for food sensitivities
• It’s free of artificial colors, preservatives or flavors
• Your dog will benefit from Canidae’s HealthPLUS blend of antioxidants, omega-3, and omega-6 fatty acids and prebiotics added after cooking. Expect your dog to have better immunity and healthy skin, coat, among other benefits.

Additional information

• First ingredients: Salmon, salmon meal, menhaden fish meal, sweet potatoes, peas, canola oil, sun-cured alfalfa, potatoes, natural flavor, and taurine.
• Calorie value: 3,880 kcal/kg or about 496 kcal/cup
• Guaranteed analysis: Crude protein (min): 32.0%, crude fat (min):18.0%, crude fiber: (max) 4.0%, moisture (max): 10.0%, linoleic acid (omega-6) min: 3.70%, alpha linolenic acid (min): 1.00%, vitamin E (min): 50 IU/kg, naturally occurring glucosamine (min): 1,200.00 mg/kg, naturally occurring chondroitin sulfate (min): 500 mg/kg, and lactobacillus acidophilus (min): 100 million CFU/lb.

Canidae also has a Grain-Free Pure Sea with Salmon and Mackerel, which is equally good.

10. Royal Canin Canine Selected Protein Adult PR Potato Rabbit Dry Dog Food

Royal Canin Canine Selected Protein Adult PR Dry Dog Food is a veterinary exclusive novel protein dog food made with potato and rabbit ideal for canines that suffer from food sensitivities.

• Uses rabbit meal as its only animal protein source while protein from soy is hydrolyzed to ensure it doesn’t cause any allergic reaction.
• It is highly digestible and very palatable
• Has added E.P.A. and D.H.A. from omega fatty acids to support healthy skin and a shiny, lustrous coat.
• Complete and balanced for adult maintenance, making it suitable for both long-term and trial feeding.

Cons

• Like other veterinary exclusive diets, it costs much more.

Additional information

• First ingredients: Dried potato, rabbit meal, coconut oil, hydrolyzed soy protein, potato protein, natural flavors, vegetable oil, monocalcium phosphate, and fish oil.
• Calorie content: On as fed basis, it has a calculated calorie value of 3495 kcal of metabolizable energy (M.E.) per kilogram of the food or an equivalent of 287 kilocalories M.E. per cup
• Guaranteed analysis: Crude Protein (min): 19.5%, Crude Fat (min): 10.5%, Crude Fiber (max): 3.7%, Moisture (max):10.0%, Omega 3 Fatty Acids (min): 0.35%, Eicosapentaenoic Acid (min): 0.12%, Docosahexaenoic Acid (min): 0.05%.

11. Blue Buffalo Natural Veterinary Diets N.P. Novel Protein – Alligator

Does your dog suffer from G.I. disease or diet-related skin inflammation? BLUE NP Novel Protein – Alligator, is a delicious veterinary diet that will help resolve these issues meant for dogs of all life stages.

• Alligator is the only animal protein source, which happens to be low cholesterol and fats, ideal for maintaining reasonable body weight.
•  It doesn’t have by-product meals of chicken or poultry as well as red meat, which is common allergens.
• It’s free of corn, wheat, soy, artificial preservatives or flavors.

Cons

• It is costly.

Additional information

• First ingredient: Deboned alligator, peas, pea starch, alligator meal, pea protein, tapioca starch, potato starch, canola oil (source of omega 6 fatty acids), and flaxseed (source of omega-3 fatty acids).
• Calories content:  3,568 kcal per kg or about 372 kcal per cup.
• Guaranteed analysis: Crude protein (min): 30.0%, crude fat (min):15.0%, crude fiber: (max) 4.0%, moisture (max): 9.0%, calcium (min):  1.5%, phosphorus (min): 1.0%, omega-3 fatty acids (min): 1.75%, omega-6 fatty acids (min): 2.1%, Ascorbic Acid (Vitamin C) (min): 100mg/kg, DHA (min): 0.2%, vitamin E (min): 300 IU/kg, and choline (min): 3500 mg/kg, Taurine (min): 0.2%, Magnesium (max): 0.12%.

Other great novel protein dog foods

1. Purina Pro Plan Focus Adult Sensitive Skin & Stomach Salmon & Rice Formula Dry Dog Food
2. Blue Buffalo Basics Limited Ingredient Grain-Free Turkey & Potato Senior Canned Dog Food, Senior Dog
3. Orijen 6 Fish Grain-Free Formula Dry Dog Food 
4. Natural Balance L.I.D. Limited Ingredient Diets Lamb & Brown Rice Formula Small Breed Dry Dog Food
5. Merrick Limited Ingredient Diet Grain-Free Dry Cat Food Real Salmon
6. Canine Caviar Limited Ingredient Open Meadow Dog Food
7. Taste of the Wild Pacific Stream Grain-Free Dry Dog Food
8. Zignature Guinea Fowl Limited Ingredient Formula Grain-Free
9. GO! SOLUTIONS™ SENSITIVITIES Limited Ingredient Pollock Recipe
10. P.S. For Dogs 100% Hypoallergenic Dog Food

Best novel protein dog treats

If you need novel protein treats, some of the top brands to buy include:

• Blue Buffalo Basics Limited Ingredient Diet, Grain-Free Turkey, and Potato Biscuits
• Natural Balance L.I.T. Limited Ingredient Treats Sweet Potato & Venison Formula Dog Treats
• Natural Balance L.I.T. Limited Ingredient Treats Sweet Potato & Bison Formula Dog Treats
• Mosaic Ostrich Burgers Exotic Dog Treats

Introducing novel protein dog foods

Once you have decided on the best novel protein food, ensure you eliminate flavored medicine, supplements, bones, treats, or any other potential source of offending ingredients. Also, please wash your hands after eating as they may lick it.

Begin your feeding trial with a small amount of the new diet and gradually increase it as you reduce on the older diet to minimize instances of temporary stomach upset and diarrhea that often occurs in the case of a rapid diet transition. This transition should take a duration of one to two weeks.

After a successful transitioning to a novel protein diet, continue giving it to your canine for about 8-12 weeks before you can judge its efficacy. During this time, ensure your pet eats nothing that has offending ingredients.

Finally, if during feeding trial, you find several diets that don’t cause allergies, consider rotating them as this will reduce the likelihood of your pet developing hypersensitivities even if fed for a long time