Using integers for registered date claims is deprecated, please use DateTimeImmutable objects instead
Stefan Bogdanescu
Founder & Senior Architect · 2026-06-29
# Moving Beyond Integers: Why You Must Use `DateTimeImmutable` for Date Claims in Laravel Passport
As developers working within the Laravel ecosystem, we constantly adapt to evolving PHP standards and framework updates. Recently, many of us have encountered a specific deprecation warning: "Using integers for registered date claims is deprecated, please use `DateTimeImmutable` objects instead." This message often surfaces when dealing with security-sensitive operations, such as generating personal access tokens via Laravel Passport, highlighting a necessary shift in how we handle temporal data.
This post will dive deep into why this change is happening, demonstrate the practical implications for your applications, and show you exactly how to migrate safely to the recommended approach using `DateTimeImmutable` objects.
## Understanding the Shift: Integers vs. Objects
The core issue lies in PHP’s evolution regarding date and time handling. Historically, dates were often stored as Unix timestamps—simple integers representing seconds or milliseconds since the epoch. While functional, this method lacks semantic context and type safety.
Modern object-oriented programming favors using dedicated classes for complex concepts. By requiring `DateTimeImmutable` objects instead of raw integers, Laravel and Passport are enforcing a stricter contract: they now require explicit, immutable temporal objects to ensure that date information is handled correctly, unambiguously, and safely across the application lifecycle. This move aligns with broader best practices in modern PHP development, much like how robust frameworks strive for consistency, echoing principles we see when designing systems on platforms like [laravelcompany.com](https://laravelcompany.com).
## The Problem in Context: Token Generation
When Laravel Passport generates tokens, it needs to serialize claims (like registration dates) into the token payload. If these claims are passed as simple integers, the system cannot guarantee their format or context across different execution environments or future PHP versions.
The deprecation occurs because using raw integers for date claims introduces potential ambiguity and fragility. The framework is signaling that relying on these low-level numerical representations is no longer sufficient for secure state management.
## The Solution: Adopting `DateTimeImmutable`
The solution is straightforward: whenever you need to store or transmit a specific point in time within your application logic—especially for security, APIs, or database interactions—you should use `DateTimeImmutable`. This class ensures that date objects cannot be accidentally modified after creation, promoting data integrity.
### Practical Code Example
Consider a scenario where you are fetching a user's registration date and preparing it for a token payload:
**The Deprecated (Old) Way:**
```php
// Hypothetical code causing the warning
$registrationDate = $user->created_at; // Assume this is an integer timestamp from the DB
$tokenData = [
'user_id' => $user->id,
'registered_at' => $registrationDate // Passing an integer
];
// Passport might flag this as deprecated.
```
**The Correct (New) Way:**
To fix this, you must ensure that the data being passed to Passport is a proper `DateTimeImmutable` object:
```php
use DateTimeImmutable;
// Assume $user is an Eloquent model instance
$registrationDate = $user->created_at; // This is likely a Carbon instance if using Eloquent
if ($registrationDate instanceof \DateTimeInterface) {
// Ensure it's immutable and correctly handled
$immutableDate = new DateTimeImmutable($registrationDate->format('Y-m-d H:i:s'));
$tokenData = [
'user_id' => $user->id,
'registered_at' => $immutableDate->format(\DateTimeInterface::ATOM) // Use a standard format for serialization
];
} else {
// Handle cases where the data might be missing or in an unexpected format
throw new \Exception("Registration date is missing or invalid.");
}
// Now, when passing this structure to Passport token generation methods,
// the deprecation warning will be resolved.
```
## Conclusion: Future-Proofing Your Application
This seemingly small change—switching from integers to `DateTimeImmutable` objects—is a powerful lesson in modern software development. It forces us to write more explicit, safer, and more maintainable code. By adopting this practice, you ensure that your application interacts with temporal data using the intended, object-oriented methods provided by PHP.
As we build complex systems on frameworks like Laravel, embracing these structural changes is crucial for future compatibility and robust security. Always prioritize type safety and immutability when dealing with critical data points, ensuring your tokens and database interactions remain reliable as you continue to evolve your projects.