DateOnly

Use DateOnly when you need to work with dates exclusively, without any time information. Examples of this include handling birthdays, anniversaries, and event dates.

TimeOnly

Use TimeOnly when you require time values without any date information. Examples include representing opening/closing times, countdowns, and scheduling alarms.

Here's how you can use TimeOnly:

Benefits of using DateOnly and TimeOnly

• Clarity and Safety: These types provide clear and explicit representations of date and time values, reducing the risk of errors caused by time zone conversions and date/time mix-ups.

• Immutability: DateOnly and TimeOnly are immutable types, meaning their values cannot be changed after creation. This helps prevent unintended modifications to date and time values.

• Compact Storage: These types take up less memory compared to DateTime because they don't include time zone information, making them more efficient for certain use cases.

• Performance: Operations involving only dates or only times can be more performant using DateOnly and TimeOnly, respectively, compared to DateTime.

• Interoperability: The Date and Time provides easy conversion methods between DateTime, DateOnly, and TimeOnly, allowing seamless integration with existing code that uses DateTime.

DateTime

In C#, DateTime is a value type and commonly used in all the programming languages, You should use DateTime when you need to work with both date and time components together or when you require time zone information. 

DateTime provides a complete representation of a specific point in time, combining both date and time information along with an optional time zone offset. here you can find some use cases where DateTime is more appropriate than using DateOnly or TimeOnly

Benefits of using DateTime: 

• Recording Events: When recording events or occurrences that happen at specific points in time, you need both the date and time components. For example, logging the exact timestamp of an event is best done with DateTime.

• Time Zone Considerations: If you're dealing with events across different time zones or need to perform time zone conversions, DateTime can handle this with its time zone information. DateOnly and TimeOnly don't include time zone support.

• Calculations Involving Both Date and Time: When performing calculations that involve both date and time components, such as calculating time intervals between two points in time, DateTime is more suitable.

• Working with External APIs: Many external APIs and libraries work with DateTime objects. If you need to integrate your code with such APIs, using DateTime will simplify the data exchange.

• Database Interactions: Databases often use DateTime to store date and time values. Using DateTime aligns well with database operations and prevents unnecessary conversions.

• Serialization and Deserialization: When working with JSON or XML serialization, DateTime is the standard representation for date and time values, making it more compatible with serialization libraries.

Let's make a decision Here

Hope this article will help you, the choice between DateTime, DateOnly, and TimeOnly should be driven by the specific needs of your application.

If your application primarily deals with only dates or times, and you don't require time zone support or date and time together, then DateOnly and TimeOnly can be more appropriate for improved code clarity and safety. However, if you need to represent points in time with both date and time information, DateTime is the suitable choice.