How to read expiration dates - is the sell-by date the expiration date?
There are a few phrases used on products for date-labeling. They include:
- "Best if Used By/Before" — The product will have the best flavor or quality within this date. It is not a purchase or safety date.
- "Sell-By" — This date tells the store how long to display the product for sale, helping with inventory management. So, is the sell-by date the expiration date? No, it isn't.
- “Use-By" — This date is the last date recommended for the use of the product while at peak quality. It is not a safety date (except for when used on infant formula).
- Expiration date (EXP) — According to Cambridge Dictionary this is "the last day on which a product or service can be used". However, according to USDA, foods are still safe for consumption after expiration dates pass. A consumer should make sure to look out for an off odor, flavor, or texture that means the food has spoiled and should not be eaten. To learn about the cosmetic expiration date, check the section below.
The regulations regarding date labeling may differ depending on the country. Please, check your local regulations.
Shelf life and cosmetic expiration dates
A product’s “shelf life” means the length of time you can expect a product to look and act as expected and to be safe for use. This time can vary depending on the type of product, how it is used, and how it is stored.
Cosmetics, like most products, start to degrade over time. It can be caused by the preservatives breaking down, exposure to bacteria and fungi while using (e.g., mascaras), exposure to moisture, separation of emulsions, etc. In the U.S., there are no laws or regulations that require cosmetics to have specific shelf lives or expiration dates on their labels.
Don't worry if you can't see a specific date on a product; manufacturers are responsible for making sure their products are safe. Remember that the length of time you can safely use your cosmetics also depends on you. Store them properly, keep containers and applicators clean, and try not to share makeup.
How to use the expiration date calculator?
Using the expiration calculator is really easy. Just follow these steps:
- Enter the starting date, e.g., production date or the date of first use.
- What is the shelf life of the product? Enter the number of days, weeks, months, years, or years and months.
- That's it! You will see the final date your product is still valid and good to use.
Example
Understanding Expiration Date Calculations
Expiration date calculations are essential for tracking product lifespan, food safety, medication effectiveness, and resource management. These calculations help determine when an item should no longer be used based on a set duration.
The key concepts of expiration date calculations include:
- Adding Days to a Date: Many expiration dates are calculated by adding a set number of days to a start date.
- Adding Months to a Date: Some items have a fixed shelf life in months, requiring month-based calculations.
- Checking if a Product is Expired: Comparing today's date with the expiration date to determine validity.
Adding Days to a Date
To determine an expiration date by adding days:
- Start with the manufacturing or purchase date.
- Add the given number of days.
Example: If a product is made on Jan 1, 2025, and expires in 30 days, the expiration date is Jan 31, 2025.
Adding Months to a Date
To determine an expiration date by adding months:
- Start with the initial date.
- Add the number of months while considering varying month lengths.
Example: A subscription starting on March 15, 2025, with a 6-month duration expires on Sept 15, 2025.
Calculating Shelf Life
To determine how long an item remains usable:
- Find the shelf life duration (in days, months, or years).
- Add it to the production or purchase date.
Example: A milk carton with a 10-day shelf life purchased on June 1, 2025, expires on June 11, 2025.
Checking if a Product is Expired
To check whether a product is still valid:
- Compare today's date with the expiration date.
- If today’s date is past the expiration date, the product is expired.
Example: A medicine with an expiration date of May 5, 2025, is expired if today's date is May 10, 2025.
Real-life Applications of Expiration Date Calculations
These calculations are widely used in daily life, including:
- Tracking food expiry to avoid waste and health risks.
- Monitoring medication effectiveness and safety.
- Managing inventory in retail and warehouse settings.
Common Operations in Expiration Date Calculations
When performing expiration-related calculations, common operations include:
- Adding or subtracting days to adjust for storage conditions.
- Comparing dates to determine remaining shelf life.
- Using percentages to estimate product usability over time.
Example: A medication with a 1-year shelf life purchased on Dec 1, 2024, will expire on Dec 1, 2025.
| Calculation Type | Description | Steps to Calculate | Example |
|---|---|---|---|
| Adding Days to a Date | Calculate an expiration date by adding a given number of days. |
|
Manufacturing date: Jan 1, 2025 Expires in 30 days → Expiration date: Jan 31, 2025 |
| Adding Months to a Date | Calculate an expiration date by adding months. |
|
Start date: March 15, 2025 Expires in 6 months → Expiration date: Sept 15, 2025 |
| Calculating Shelf Life | Determine how long a product remains usable before expiry. |
|
Milk with a 10-day shelf life bought on June 1 → Expires on June 11 |
| Checking if a Product is Expired | Determine if the expiration date has passed. |
|
Expiration date: May 5, 2025 Today's date: May 10, 2025 → Product is expired |
| Real-life Applications | Using expiration date calculations in daily scenarios. |
|
A medication with a 1-year shelf life purchased on Dec 1, 2024 → Expires on Dec 1, 2025 |
